<- STD Index (1..100)
STD 92
(also RFC 8010, RFC 8011)
[Note that this file is a concatenation of more than one RFC.]
Internet Engineering Task Force (IETF) M. Sweet
Request for Comments: 8010 Apple Inc.
Obsoletes: 2910, 3382 I. McDonald
Category: Standards Track High North, Inc.
ISSN: 2070-1721 January 2017
Internet Printing Protocol/1.1: Encoding and Transport
Abstract
The Internet Printing Protocol (IPP) is an application-level protocol
for distributed printing using Internet tools and technologies. This
document defines the rules for encoding IPP operations, attributes,
and values into the Internet MIME media type called
"application/ipp". It also defines the rules for transporting a
message body whose Content-Type is "application/ipp" over HTTP and/or
HTTPS. The IPP data model and operation semantics are described in
"Internet Printing Protocol/1.1: Model and Semantics" (RFC 8011).
This document obsoletes RFCs 2910 and 3382.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8010.
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Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions Used in This Document . . . . . . . . . . . . . . 5
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 5
2.2. Printing Terminology . . . . . . . . . . . . . . . . . . 5
2.3. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 6
3. Encoding of the Operation Layer . . . . . . . . . . . . . . . 6
3.1. Picture of the Encoding . . . . . . . . . . . . . . . . . 8
3.1.1. Request and Response . . . . . . . . . . . . . . . . 8
3.1.2. Attribute Group . . . . . . . . . . . . . . . . . . . 9
3.1.3. Attribute . . . . . . . . . . . . . . . . . . . . . . 9
3.1.4. Attribute-with-one-value . . . . . . . . . . . . . . 10
3.1.5. Additional-value . . . . . . . . . . . . . . . . . . 11
3.1.6. Collection Attribute . . . . . . . . . . . . . . . . 12
3.1.7. Member Attributes . . . . . . . . . . . . . . . . . . 13
3.1.8. Alternative Picture of the Encoding of a Request or a
Response . . . . . . . . . . . . . . . . . . . . . . 14
3.2. Syntax of Encoding . . . . . . . . . . . . . . . . . . . 15
3.3. Attribute-group . . . . . . . . . . . . . . . . . . . . . 16
3.4. Required Parameters . . . . . . . . . . . . . . . . . . . 18
3.4.1. "version-number" . . . . . . . . . . . . . . . . . . 18
3.4.2. "operation-id" . . . . . . . . . . . . . . . . . . . 18
3.4.3. "status-code" . . . . . . . . . . . . . . . . . . . . 19
3.4.4. "request-id" . . . . . . . . . . . . . . . . . . . . 19
3.5. Tags . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.5.1. "delimiter-tag" Values . . . . . . . . . . . . . . . 19
3.5.2. "value-tag" Values . . . . . . . . . . . . . . . . . 20
3.6. "name-length" . . . . . . . . . . . . . . . . . . . . . . 23
3.7. (Attribute) "name" . . . . . . . . . . . . . . . . . . . 23
3.8. "value-length" . . . . . . . . . . . . . . . . . . . . . 23
3.9. (Attribute) "value" . . . . . . . . . . . . . . . . . . . 24
3.10. Data . . . . . . . . . . . . . . . . . . . . . . . . . . 25
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4. Encoding of Transport Layer . . . . . . . . . . . . . . . . . 26
4.1. Printer URI, Job URI, and Job ID . . . . . . . . . . . . 26
5. IPP URI Schemes . . . . . . . . . . . . . . . . . . . . . . . 28
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 29
7. Internationalization Considerations . . . . . . . . . . . . . 31
8. Security Considerations . . . . . . . . . . . . . . . . . . . 31
8.1. Security Conformance Requirements . . . . . . . . . . . . 31
8.1.1. Digest Authentication . . . . . . . . . . . . . . . . 32
8.1.2. Transport Layer Security (TLS) . . . . . . . . . . . 32
8.2. Using IPP with TLS . . . . . . . . . . . . . . . . . . . 33
9. Interoperability with Other IPP Versions . . . . . . . . . . 33
9.1. The "version-number" Parameter . . . . . . . . . . . . . 34
9.2. Security and URI Schemes . . . . . . . . . . . . . . . . 34
10. Changes since RFC 2910 . . . . . . . . . . . . . . . . . . . 35
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 36
11.1. Normative References . . . . . . . . . . . . . . . . . . 36
11.2. Informative References . . . . . . . . . . . . . . . . . 38
Appendix A. Protocol Examples . . . . . . . . . . . . . . . . . 40
A.1. Print-Job Request . . . . . . . . . . . . . . . . . . . . 40
A.2. Print-Job Response (Successful) . . . . . . . . . . . . . 41
A.3. Print-Job Response (Failure) . . . . . . . . . . . . . . 42
A.4. Print-Job Response (Success with Attributes Ignored) . . 43
A.5. Print-URI Request . . . . . . . . . . . . . . . . . . . . 45
A.6. Create-Job Request . . . . . . . . . . . . . . . . . . . 46
A.7. Create-Job Request with Collection Attributes . . . . . . 46
A.8. Get-Jobs Request . . . . . . . . . . . . . . . . . . . . 48
A.9. Get-Jobs Response . . . . . . . . . . . . . . . . . . . . 49
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 51
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 51
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1. Introduction
This document contains the rules for encoding IPP operations and
describes two layers: the transport layer and the operation layer.
The transport layer consists of an HTTP request and response. All
IPP implementations support HTTP/1.1, the relevant parts of which are
described in the following RFCs:
o Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing
[RFC7230]
o Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content
[RFC7231]
o Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests
[RFC7232]
o Hypertext Transfer Protocol (HTTP/1.1): Caching [RFC7234]
o Hypertext Transfer Protocol (HTTP/1.1): Authentication [RFC7235]
o The 'Basic' HTTP Authentication Scheme [RFC7617]
o HTTP Digest Access Authentication [RFC7616]
IPP implementations can support HTTP/2, which is described in the
following RFCs:
o Hypertext Transfer Protocol Version 2 (HTTP/2) [RFC7540]
o HPACK - Header Compression for HTTP/2 [RFC7541]
This document specifies the HTTP headers that an IPP implementation
supports.
The operation layer consists of a message body in an HTTP request or
response. The "Internet Printing Protocol/1.1: Model and Semantics"
document [RFC8011] and subsequent extensions (collectively known as
the IPP Model) define the semantics of such a message body and the
supported values. This document specifies the encoding of an IPP
request and response message.
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2. Conventions Used in This Document
2.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2.2. Printing Terminology
Client: Initiator of outgoing IPP session requests and sender of
outgoing IPP operation requests (Hypertext Transfer Protocol --
HTTP/1.1 [RFC7230] User Agent).
Document: An object created and managed by a Printer that contains
description, processing, and status information. A Document object
may have attached data and is bound to a single Job.
'ipp' URI: An IPP URI as defined in [RFC3510].
'ipps' URI: An IPPS URI as defined in [RFC7472].
Job: An object created and managed by a Printer that contains
description, processing, and status information. The Job also
contains zero or more Document objects.
Logical Device: A print server, software service, or gateway that
processes Jobs and either forwards or stores the processed Job or
uses one or more Physical Devices to render output.
Model: The semantics of operations, attributes, values, and status-
codes used in the Internet Printing Protocol as defined in the
Internet Printing Protocol/1.1: Model and Semantics document
[RFC8011] and subsequent extensions.
Output Device: A single Logical or Physical Device.
Physical Device: A hardware implementation of an endpoint device,
e.g., a marking engine, a fax modem, etc.
Printer: Listener for incoming IPP session requests and receiver of
incoming IPP operation requests (Hypertext Transfer Protocol --
HTTP/1.1 [RFC7230] Server) that represents one or more Physical
Devices or a Logical Device.
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2.3. Abbreviations
ABNF: Augmented Backus-Naur Form [RFC5234]
ASCII: American Standard Code for Information Interchange [RFC20]
HTTP: Hypertext Transfer Protocol [RFC7230]
HTTPS: HTTP over TLS [RFC2818]
IANA: Internet Assigned Numbers Authority
IEEE: Institute of Electrical and Electronics Engineers
IESG: Internet Engineering Steering Group
IPP: Internet Printing Protocol (this document and [PWG5100.12])
ISTO: IEEE Industry Standards and Technology Organization
LPD: Line Printer Daemon Protocol [RFC1179]
PWG: IEEE-ISTO Printer Working Group
RFC: Request for Comments
TCP: Transmission Control Protocol [RFC793]
TLS: Transport Layer Security [RFC5246]
URI: Uniform Resource Identifier [RFC3986]
URL: Uniform Resource Locator [RFC3986]
UTF-8: Unicode Transformation Format - 8-bit [RFC3629]
3. Encoding of the Operation Layer
The operation layer is the message body part of the HTTP request or
response and it MUST contain a single IPP operation request or IPP
operation response. Each request or response consists of a sequence
of values and attribute groups. Attribute groups consist of a
sequence of attributes each of which is a name and value. Names and
values are ultimately sequences of octets.
The encoding consists of octets as the most primitive type. There
are several types built from octets, but three important types are
integers, character strings, and octet strings, on which most other
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data types are built. Every character string in this encoding MUST
be a sequence of characters where the characters are associated with
some charset [RFC2978] and some natural language. A character string
MUST be in "reading order" with the first character in the value
(according to reading order) being the first character in the
encoding. A character string whose associated charset is US-ASCII
and whose associated natural language is US English is henceforth
called a US-ASCII-STRING. A character string whose associated
charset and natural language are specified in a request or response
as described in the Model is henceforth called a LOCALIZED-STRING.
An octet string MUST be in "Model order" with the first octet in the
value (according to the Model order) being the first octet in the
encoding. Every integer in this encoding MUST be encoded as a signed
integer using two's-complement binary encoding with big-endian format
(also known as "network order" and "most significant byte first").
The number of octets for an integer MUST be 1, 2, or 4, depending on
usage in the protocol. A one-octet integer, henceforth called a
SIGNED-BYTE, is used for the version-number and tag fields. A two-
byte integer, henceforth called a SIGNED-SHORT, is used for the
operation-id, status-code, and length fields. A four-byte integer,
henceforth called a SIGNED-INTEGER, is used for value fields and the
request-id.
The following two sections present the encoding of the operation
layer in two ways:
o informally through pictures and description
o formally through Augmented Backus-Naur Form (ABNF), as specified
by RFC 5234 [RFC5234]
An operation request or response MUST use the encoding described in
these two sections.
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3.1. Picture of the Encoding
3.1.1. Request and Response
An operation request or response is encoded as follows:
-----------------------------------------------
| version-number | 2 bytes - required
-----------------------------------------------
| operation-id (request) |
| or | 2 bytes - required
| status-code (response) |
-----------------------------------------------
| request-id | 4 bytes - required
-----------------------------------------------
| attribute-group | n bytes - 0 or more
-----------------------------------------------
| end-of-attributes-tag | 1 byte - required
-----------------------------------------------
| data | q bytes - optional
-----------------------------------------------
Figure 1: IPP Message Format
The first three fields in the above diagram contain the value of
attributes described in Section 4.1.1 of the Model and Semantics
document [RFC8011].
The fourth field is the "attribute-group" field, and it occurs 0 or
more times. Each "attribute-group" field represents a single group
of attributes, such as an Operation Attributes group or a Job
Attributes group (see the Model). The Model specifies the required
attribute groups and their order for each operation request and
response.
The "end-of-attributes-tag" field is always present, even when the
"data" is not present. The Model specifies whether the "data" field
is present for each operation request and response.
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3.1.2. Attribute Group
Each "attribute-group" field is encoded as follows:
-----------------------------------------------
| begin-attribute-group-tag | 1 byte
----------------------------------------------------------
| attribute | p bytes |- 0 or more
----------------------------------------------------------
Figure 2: Attribute Group Encoding
An "attribute-group" field contains zero or more "attribute" fields.
Note that the values of the "begin-attribute-group-tag" field and the
"end-of-attributes-tag" field are called "delimiter-tags".
3.1.3. Attribute
An "attribute" field is encoded as follows:
-----------------------------------------------
| attribute-with-one-value | q bytes
----------------------------------------------------------
| additional-value | r bytes |- 0 or more
----------------------------------------------------------
Figure 3: Attribute Encoding
When an attribute is single valued (e.g., "copies" with a value of
10) or multi-valued with one value (e.g., "sides-supported" with just
the value 'one-sided'), it is encoded with just an "attribute-with-
one-value" field. When an attribute is multi-valued with n values
(e.g., "sides-supported" with the values 'one-sided' and 'two-sided-
long-edge'), it is encoded with an "attribute-with-one-value" field
followed by n-1 "additional-value" fields.
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3.1.4. Attribute-with-one-value
Each "attribute-with-one-value" field is encoded as follows:
-----------------------------------------------
| value-tag | 1 byte
-----------------------------------------------
| name-length (value is u) | 2 bytes
-----------------------------------------------
| name | u bytes
-----------------------------------------------
| value-length (value is v) | 2 bytes
-----------------------------------------------
| value | v bytes
-----------------------------------------------
Figure 4: Single Value Attribute Encoding
An "attribute-with-one-value" field is encoded with five subfields:
o The "value-tag" field specifies the attribute syntax, e.g., 0x44
for the attribute syntax 'keyword'.
o The "name-length" field specifies the length of the "name" field
in bytes, e.g., u in the above diagram or 15 for the name "sides-
supported".
o The "name" field contains the textual name of the attribute, e.g.,
"sides-supported".
o The "value-length" field specifies the length of the "value" field
in bytes, e.g., v in the above diagram or 9 for the (keyword)
value 'one-sided'.
o The "value" field contains the value of the attribute, e.g., the
textual value 'one-sided'.
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3.1.5. Additional-value
Each "additional-value" field is encoded as follows:
-----------------------------------------------
| value-tag | 1 byte
-----------------------------------------------
| name-length (value is 0x0000) | 2 bytes
-----------------------------------------------
| value-length (value is w) | 2 bytes
-----------------------------------------------
| value | w bytes
-----------------------------------------------
Figure 5: Additional Attribute Value Encoding
An "additional-value" is encoded with four subfields:
o The "value-tag" field specifies the attribute syntax, e.g., 0x44
for the attribute syntax 'keyword'.
o The "name-length" field has the value of 0 in order to signify
that it is an "additional-value". The value of the "name-length"
field distinguishes an "additional-value" field ("name-length" is
0) from an "attribute-with-one-value" field ("name-length" is not
0).
o The "value-length" field specifies the length of the "value" field
in bytes, e.g., w in the above diagram or 19 for the (keyword)
value 'two-sided-long-edge'.
o The "value" field contains the value of the attribute, e.g., the
textual value 'two-sided-long-edge'.
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3.1.6. Collection Attribute
Collection attributes create a named group containing related
"member" attributes. The "attribute-with-one-value" field for a
collection attribute is encoded as follows:
-----------------------------------------------
| value-tag (value is 0x34) | 1 byte
-----------------------------------------------
| name-length (value is u) | 2 bytes
-----------------------------------------------
| name | u bytes
-----------------------------------------------
| value-length (value is 0x0000) | 2 bytes
-----------------------------------------------------------
| member-attribute | q bytes |-0 or more
-----------------------------------------------------------
| end-value-tag (value is 0x37) | 1 byte
-----------------------------------------------
| end-name-length (value is 0x0000) | 2 bytes
-----------------------------------------------
| end-value-length (value is 0x0000) | 2 bytes
-----------------------------------------------
Figure 6: Collection Attribute Encoding
Collection attribute is encoded with eight subfields:
o The "value-tag" field specifies the start attribute syntax: 0x34
for the attribute syntax 'begCollection'.
o The "name-length" field specifies the length of the "name" field
in bytes, e.g., u in the above diagram or 9 for the name "media-
col". Additional collection attribute values use a name length of
0x0000.
o The "name" field contains the textual name of the attribute, e.g.,
"media-col".
o The "value-length" field specifies a length of 0x0000.
o The "member-attribute" field contains member attributes encoded as
defined in Section 3.1.7.
o The "end-value-tag" field specifies the end attribute syntax: 0x37
for the attribute syntax 'endCollection'.
o The "end-name-length" field specifies a length of 0x0000.
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o The "end-value-length" field specifies a length of 0x0000.
3.1.7. Member Attributes
Each "member-attribute" field is encoded as follows:
-----------------------------------------------
| value-tag (value is 0x4a) | 1 byte
-----------------------------------------------
| name-length (value is 0x0000) | 2 bytes
-----------------------------------------------
| value-length (value is w) | 2 bytes
-----------------------------------------------
| value (member-name) | w bytes
-----------------------------------------------
| member-value-tag | 1 byte
-----------------------------------------------
| name-length (value is 0x0000) | 2 bytes
-----------------------------------------------
| member-value-length (value is x) | 2 bytes
-----------------------------------------------
| member-value | x bytes
-----------------------------------------------
Figure 7: Member Attribute Encoding
A "member-attribute" is encoded with eight subfields:
o The "value-tag" field specifies 0x4a for the attribute syntax
'memberAttrName'.
o The "name-length" field has the value of 0 in order to signify
that it is a "member-attribute" contained in the collection.
o The "value-length" field specifies the length of the "value" field
in bytes, e.g., w in the above diagram or 10 for the member
attribute name 'media-type'. Additional member attribute values
are specified using a value length of 0.
o The "value" field contains the name of the member attribute, e.g.,
the textual value 'media-type'.
o The "member-value-tag" field specifies the attribute syntax for
the member attribute, e.g., 0x44 for the attribute syntax
'keyword'.
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o The second "name-length" field has the value of 0 in order to
signify that it is a "member-attribute" contained in the
collection.
o The "member-value-length" field specifies the length of the member
attribute value, e.g., x in the above diagram or 10 for the value
'stationery'.
o The "member-value" field contains the value of the attribute,
e.g., the textual value 'stationery'.
3.1.8. Alternative Picture of the Encoding of a Request or a Response
From the standpoint of a parser that performs an action based on a
"tag" value, the encoding consists of:
-----------------------------------------------
| version-number | 2 bytes - required
-----------------------------------------------
| operation-id (request) |
| or | 2 bytes - required
| status-code (response) |
-----------------------------------------------
| request-id | 4 bytes - required
-----------------------------------------------------------
| tag (delimiter-tag or value-tag) | 1 byte |
----------------------------------------------- |-0 or more
| empty or rest of attribute | x bytes |
-----------------------------------------------------------
| end-of-attributes-tag | 1 byte - required
-----------------------------------------------
| data | y bytes - optional
-----------------------------------------------
Figure 8: Encoding Based on Value Tags
The following shows what fields the parser would expect after each
type of "tag":
o "begin-attribute-group-tag": expect zero or more "attribute"
fields
o "value-tag": expect the remainder of an "attribute-with-one-value"
or an "additional-value"
o "end-of-attributes-tag": expect that "attribute" fields are
complete and there is optional "data"
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3.2. Syntax of Encoding
The ABNF [RFC5234] syntax for an IPP message is shown in Figure 9.
ipp-message = ipp-request / ipp-response
ipp-request = version-number operation-id request-id
*attribute-group end-of-attributes-tag data
ipp-response = version-number status-code request-id
*attribute-group end-of-attributes-tag data
version-number = major-version-number minor-version-number
major-version-number = SIGNED-BYTE
minor-version-number = SIGNED-BYTE
operation-id = SIGNED-SHORT ; mapping from model
status-code = SIGNED-SHORT ; mapping from model
request-id = SIGNED-INTEGER ; whose value is > 0
attribute-group = begin-attribute-group-tag *attribute
attribute = attribute-with-one-value *additional-value
attribute-with-one-value = value-tag name-length name
value-length value
additional-value = value-tag zero-name-length
value-length value
name-length = SIGNED-SHORT ; number of octets of 'name'
name = LALPHA *( LALPHA / DIGIT / "-" / "_" / "." )
value-length = SIGNED-SHORT ; number of octets of 'value'
value = OCTET-STRING
data = OCTET-STRING
zero-name-length = %x00.00 ; name-length of 0
value-tag = %x10-ff ; see Section 3.5.2
begin-attribute-group-tag = %x00-02 / %x04-0f ; see Section 3.5.1
end-of-attributes-tag = %x03 ; tag of 3
; see Section 3.5.1
SIGNED-BYTE = BYTE
SIGNED-SHORT = 2BYTE
SIGNED-INTEGER = 4BYTE
DIGIT = %x30-39 ; "0" to "9"
LALPHA = %x61-7A ; "a" to "z"
BYTE = %x00-ff
OCTET-STRING = *BYTE
Figure 9: ABNF of IPP Message Format
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Figure 10 defines additional terms that are referenced in this
document and provides an alternate grouping of the delimiter tags.
delimiter-tag = begin-attribute-group-tag / ; see Section 3.5.1
end-of-attributes-tag
begin-attribute-group-tag = %x00 / operation-attributes-tag /
job-attributes-tag / printer-attributes-tag /
unsupported-attributes-tag / future-group-tags
operation-attributes-tag = %x01 ; tag of 1
job-attributes-tag = %x02 ; tag of 2
end-of-attributes-tag = %x03 ; tag of 3
printer-attributes-tag = %x04 ; tag of 4
unsupported-attributes-tag = %x05 ; tag of 5
future-group-tags = %x06-0f ; future extensions
Figure 10: ABNF for Attribute Group Tags
3.3. Attribute-group
Each "attribute-group" field MUST be encoded with the "begin-
attribute-group-tag" field followed by zero or more "attribute" sub-
fields.
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Table 1 maps the Model group name to value of the "begin-attribute-
group-tag" field:
+----------------+--------------------------------------------------+
| Model Document | "begin-attribute-group-tag" field values |
| Group | |
+----------------+--------------------------------------------------+
| Operation | "operations-attributes-tag" |
| Attributes | |
+----------------+--------------------------------------------------+
| Job Template | "job-attributes-tag" |
| Attributes | |
+----------------+--------------------------------------------------+
| Job Object | "job-attributes-tag" |
| Attributes | |
+----------------+--------------------------------------------------+
| Unsupported | "unsupported-attributes-tag" |
| Attributes | |
+----------------+--------------------------------------------------+
| Requested | (Get-Job-Attributes) "job-attributes-tag" |
| Attributes | |
+----------------+--------------------------------------------------+
| Requested | (Get-Printer-Attributes)"printer-attributes-tag" |
| Attributes | |
+----------------+--------------------------------------------------+
| Document | in a special position at the end of the message |
| Content | as described in Section 3.1.1. |
+----------------+--------------------------------------------------+
Table 1: Group Values
For each operation request and response, the Model prescribes the
required and optional attribute groups, along with their order.
Within each attribute group, the Model prescribes the required and
optional attributes, along with their order.
When the Model requires an attribute group in a request or response
and the attribute group contains zero attributes, a request or
response SHOULD encode the attribute group with the "begin-attribute-
group-tag" field followed by zero "attribute" fields. For example,
if the Client requests a single unsupported attribute with the Get-
Printer-Attributes operation, the Printer MUST return no "attribute"
fields, and it SHOULD return a "begin-attribute-group-tag" field for
the Printer Attributes group. The Unsupported Attributes group is
not such an example. According to the Model, the Unsupported
Attributes group SHOULD be present only if the Unsupported Attributes
group contains at least one attribute.
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A receiver of a request MUST be able to process the following as
equivalent empty attribute groups:
a. A "begin-attribute-group-tag" field with zero following
"attribute" fields.
b. A missing, but expected, "begin-attribute-group-tag" field.
When the Model requires a sequence of an unknown number of attribute
groups, each of the same type, the encoding MUST contain one "begin-
attribute-group-tag" field for each attribute group, even when an
"attribute-group" field contains zero "attribute" sub-fields. For
example, the Get-Jobs operation may return zero attributes for some
Jobs and not others. The "begin-attribute-group-tag" field followed
by zero "attribute" fields tells the recipient that there is a Job in
queue for which no information is available except that it is in the
queue.
3.4. Required Parameters
Some operation elements are called parameters in the Model. They
MUST be encoded in a special position and they MUST NOT appear as
operation attributes. These parameters are described in the
subsections below.
3.4.1. "version-number"
The "version-number" field consists of a major and minor version-
number, each of which is represented by a SIGNED-BYTE. The major
version-number is the first byte of the encoding and the minor
version-number is the second byte of the encoding. The protocol
described in [RFC8011] has a major version-number of 1 (0x01) and a
minor version-number of 1 (0x01). The ABNF for these two bytes is
%x01.01.
Note: See Section 9 for more information on the "version-number"
field and IPP version numbers.
3.4.2. "operation-id"
The "operation-id" field contains an operation-id value as defined in
the Model. The value is encoded as a SIGNED-SHORT and is located in
the third and fourth bytes of the encoding of an operation request.
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3.4.3. "status-code"
The "status-code" field contains a status-code value as defined in
the Model. The value is encoded as a SIGNED-SHORT and is located in
the third and fourth bytes of the encoding of an operation response.
If an IPP status-code is returned, then the HTTP status-code MUST be
200 (OK). With any other HTTP status-code value, the HTTP response
MUST NOT contain an IPP message body, and thus no IPP status-code is
returned.
3.4.4. "request-id"
The "request-id" field contains the request-id value as defined in
the Model. The value is encoded as a SIGNED-INTEGER and is located
in the fifth through eighth bytes of the encoding.
3.5. Tags
There are two kinds of tags:
o delimiter tags: delimit major sections of the protocol, namely
attribute groups and data
o value tags: specify the type of each attribute value
Tags are part of the IANA IPP registry [IANA-IPP]
3.5.1. "delimiter-tag" Values
Table 2 specifies the values for the delimiter tags defined in this
document. These tags are registered, along with tags defined in
other documents, in the "Attribute Group Tags" registry.
+-----------------+------------------------------+
| Tag Value (Hex) | Meaning |
+-----------------+------------------------------+
| 0x00 | Reserved |
| 0x01 | "operation-attributes-tag" |
| 0x02 | "job-attributes-tag" |
| 0x03 | "end-of-attributes-tag" |
| 0x04 | "printer-attributes-tag" |
| 0x05 | "unsupported-attributes-tag" |
+-----------------+------------------------------+
Table 2: "delimiter-tag" Values
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When a "begin-attribute-group-tag" field occurs in the protocol, it
means that zero or more following attributes up to the next group tag
are attributes belonging to the attribute group specified by the
value of the "begin-attribute-group-tag". For example, if the value
of "begin-attribute-group-tag" is 0x01, the following attributes are
members of the Operations Attributes group.
The "end-of-attributes-tag" (value 0x03) MUST occur exactly once in
an operation and MUST be the last "delimiter-tag". If the operation
has a document-data group, the Document data in that group follows
the "end-of-attributes-tag".
The order and presence of "attribute-group" fields (whose beginning
is marked by the "begin-attribute-group-tag" subfield) for each
operation request and each operation response MUST be that defined in
the Model.
A Printer MUST treat a "delimiter-tag" (values from 0x00 through
0x0f) differently from a "value-tag" (values from 0x10 through 0xff)
so that the Printer knows there is an entire attribute group as
opposed to a single value.
3.5.2. "value-tag" Values
The remaining tables show values for the "value-tag" field, which is
the first octet of an attribute. The "value-tag" field specifies the
type of the value of the attribute.
Table 3 specifies the "out-of-band" values for the "value-tag" field
defined in this document. These tags are registered, along with tags
defined in other documents, in the "Out-of-Band Attribute Value Tags"
registry.
+-----------------+-------------+
| Tag Value (Hex) | Meaning |
+-----------------+-------------+
| 0x10 | unsupported |
| 0x12 | unknown |
| 0x13 | no-value |
+-----------------+-------------+
Table 3: Out-of-Band Values
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Table 4 specifies the integer values defined in this document for the
"value-tag" field; they are registered in the "Attribute Syntaxes"
registry.
+----------------+--------------------------------------------------+
| Tag Value | Meaning |
| (Hex) | |
+----------------+--------------------------------------------------+
| 0x20 | Unassigned integer data type (see IANA IPP |
| | registry) |
| 0x21 | integer |
| 0x22 | boolean |
| 0x23 | enum |
| 0x24-0x2f | Unassigned integer data types (see IANA IPP |
| | registry) |
+----------------+--------------------------------------------------+
Table 4: Integer Tags
Table 5 specifies the octetString values defined in this document for
the "value-tag" field; they are registered in the "Attribute
Syntaxes" registry.
+---------------+---------------------------------------------------+
| Tag Value | Meaning |
| (Hex) | |
+---------------+---------------------------------------------------+
| 0x30 | octetString with an unspecified format |
| 0x31 | dateTime |
| 0x32 | resolution |
| 0x33 | rangeOfInteger |
| 0x34 | begCollection |
| 0x35 | textWithLanguage |
| 0x36 | nameWithLanguage |
| 0x37 | endCollection |
| 0x38-0x3f | Unassigned octetString data types (see IANA IPP |
| | registry) |
+---------------+---------------------------------------------------+
Table 5: octetString Tags
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Table 6 specifies the character-string values defined in this
document for the "value-tag" field; they are registered in the
"Attribute Syntaxes" registry.
+---------------+---------------------------------------------------+
| Tag Value | Meaning |
| (Hex) | |
+---------------+---------------------------------------------------+
| 0x40 | Unassigned character-string data type (see IANA |
| | IPP registry) |
| 0x41 | textWithoutLanguage |
| 0x42 | nameWithoutLanguage |
| 0x43 | Unassigned character-string data type (see IANA |
| | IPP registry) |
| 0x44 | keyword |
| 0x45 | uri |
| 0x46 | uriScheme |
| 0x47 | charset |
| 0x48 | naturalLanguage |
| 0x49 | mimeMediaType |
| 0x4a | memberAttrName |
| 0x4b-0x5f | Unassigned character-string data types (see IANA |
| | IPP registry) |
+---------------+---------------------------------------------------+
Table 6: String Tags
Note: An attribute value always has a type, which is explicitly
specified by its tag; one such tag value is "nameWithoutLanguage".
An attribute's name has an implicit type, which is keyword.
The values 0x60-0xff are reserved for future type definitions in
Standards Track documents.
The tag 0x7f is reserved for extending types beyond the 255 values
available with a single byte. A tag value of 0x7f MUST signify that
the first four bytes of the value field are interpreted as the tag
value. Note this future extension doesn't affect parsers that are
unaware of this special tag. The tag is like any other unknown tag,
and the value length specifies the length of a value, which contains
a value that the parser treats atomically. Values from 0x00000000 to
0x3fffffff are reserved for definition in future Standards Track
documents. The values 0x40000000 to 0x7fffffff are reserved for
vendor extensions.
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3.6. "name-length"
The "name-length" field consists of a SIGNED-SHORT and specifies the
number of octets in the immediately following "name" field. The
value of this field excludes the two bytes of the "name-length"
field. For example, if the "name" field contains 'sides', the value
of this field is 5.
If a "name-length" field has a value of zero, the following "name"
field is empty and the following value is treated as an additional
value for the attribute encoded in the nearest preceding "attribute-
with-one-value" field. Within an attribute group, if two or more
attributes have the same name, the attribute group is malformed (see
[RFC8011]). The zero-length name is the only mechanism for multi-
valued attributes.
3.7. (Attribute) "name"
The "name" field contains the name of an attribute. The Model
specifies such names.
3.8. "value-length"
The "value-length" field consists of a SIGNED-SHORT, which specifies
the number of octets in the immediately following "value" field. The
value of this field excludes the two bytes of the "value-length"
field. For example, if the "value" field contains the keyword
(string) value 'one-sided', the value of this field is 9.
For any of the types represented by binary signed integers, the
sender MUST encode the value in exactly four octets.
For any of the types represented by binary signed bytes, e.g., the
boolean type, the sender MUST encode the value in exactly one octet.
For any of the types represented by character strings, the sender
MUST encode the value with all the characters of the string and
without any padding characters.
For "out-of-band" values for the "value-tag" field defined in this
document, such as 'unsupported', the "value-length" MUST be 0 and the
"value" empty; the "value" has no meaning when the "value-tag" has
one of these "out-of-band" values. For future "out-of-band" "value-
tag" fields, the same rule holds unless the definition explicitly
states that the "value-length" MAY be non-zero and the "value" non-
empty
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3.9. (Attribute) "value"
The syntax types (specified by the "value-tag" field) and most of the
details of the representation of attribute values are defined in the
Model. Table 7 augments the information in the Model and defines the
syntax types from the Model in terms of the five basic types defined
in Section 3. The five types are US-ASCII-STRING, LOCALIZED-STRING,
SIGNED-INTEGER, SIGNED-SHORT, SIGNED-BYTE, and OCTET-STRING.
+----------------------+--------------------------------------------+
| Syntax of Attribute | Encoding |
| Value | |
+----------------------+--------------------------------------------+
| textWithoutLanguage, | LOCALIZED-STRING |
| nameWithoutLanguage | |
+----------------------+--------------------------------------------+
| textWithLanguage | OCTET-STRING consisting of four fields: a |
| | SIGNED-SHORT, which is the number of |
| | octets in the following field; a value of |
| | type natural-language; a SIGNED-SHORT, |
| | which is the number of octets in the |
| | following field; and a value of type |
| | textWithoutLanguage. The length of a |
| | textWithLanguage value MUST be 4 + the |
| | value of field a + the value of field c. |
+----------------------+--------------------------------------------+
| nameWithLanguage | OCTET-STRING consisting of four fields: a |
| | SIGNED-SHORT, which is the number of |
| | octets in the following field; a value of |
| | type natural-language; a SIGNED-SHORT, |
| | which is the number of octets in the |
| | following field; and a value of type |
| | nameWithoutLanguage. The length of a |
| | nameWithLanguage value MUST be 4 + the |
| | value of field a + the value of field c. |
+----------------------+--------------------------------------------+
| charset, | US-ASCII-STRING |
| naturalLanguage, | |
| mimeMediaType, | |
| keyword, uri, and | |
| uriScheme | |
+----------------------+--------------------------------------------+
| boolean | SIGNED-BYTE where 0x00 is 'false' and 0x01 |
| | is 'true' |
+----------------------+--------------------------------------------+
| integer and enum | a SIGNED-INTEGER |
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+----------------------+--------------------------------------------+
| dateTime | OCTET-STRING consisting of eleven octets |
| | whose contents are defined by |
| | "DateAndTime" in RFC 2579 [RFC2579] |
+----------------------+--------------------------------------------+
| resolution | OCTET-STRING consisting of nine octets of |
| | two SIGNED-INTEGERs followed by a SIGNED- |
| | BYTE. The first SIGNED-INTEGER contains |
| | the value of cross-feed direction |
| | resolution. The second SIGNED-INTEGER |
| | contains the value of feed direction |
| | resolution. The SIGNED-BYTE contains the |
| | units value. |
+----------------------+--------------------------------------------+
| rangeOfInteger | Eight octets consisting of two SIGNED- |
| | INTEGERs. The first SIGNED-INTEGER |
| | contains the lower bound and the second |
| | SIGNED-INTEGER contains the upper bound. |
+----------------------+--------------------------------------------+
| 1setOf X | Encoding according to the rules for an |
| | attribute with more than one value. Each |
| | value X is encoded according to the rules |
| | for encoding its type. |
+----------------------+--------------------------------------------+
| octetString | OCTET-STRING |
+----------------------+--------------------------------------------+
| collection | Encoding as defined in Section 3.1.6. |
+----------------------+--------------------------------------------+
Table 7: Attribute Value Encoding
The attribute syntax type of the value determines its encoding and
the value of its "value-tag".
3.10. Data
The "data" field MUST include any data required by the operation.
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4. Encoding of Transport Layer
HTTP/1.1 [RFC7230] is the REQUIRED transport layer for this protocol.
HTTP/2 [RFC7540] is an OPTIONAL transport layer for this protocol.
The operation layer has been designed with the assumption that the
transport layer contains the following information:
o the target URI for the operation; and
o the total length of the data in the operation layer, either as a
single length or as a sequence of chunks each with a length.
Printer implementations MUST support HTTP over the IANA-assigned
well-known port 631 (the IPP default port), although a Printer
implementation can support HTTP over some other port as well.
Each HTTP operation MUST use the POST method where the request-target
is the object target of the operation and where the "Content-Type" of
the message body in each request and response MUST be "application/
ipp". The message body MUST contain the operation layer and MUST
have the syntax described in Section 3.2, "Syntax of Encoding". A
Client implementation MUST adhere to the rules for a Client described
for HTTP [RFC7230]. A Printer (server) implementation MUST adhere to
the rules for an origin server described for HTTP [RFC7230].
An IPP server sends a response for each request that it receives. If
an IPP server detects an error, it MAY send a response before it has
read the entire request. If the HTTP layer of the IPP server
completes processing the HTTP headers successfully, it MAY send an
intermediate response, such as "100 Continue", with no IPP data
before sending the IPP response. A Client MUST expect such a variety
of responses from an IPP server. For further information on HTTP,
consult the HTTP documents [RFC7230].
An HTTP/1.1 server MUST support chunking for IPP requests, and an IPP
Client MUST support chunking for IPP responses according to HTTP/1.1
[RFC7230].
4.1. Printer URI, Job URI, and Job ID
All Printer and Job objects are identified by a Uniform Resource
Identifier (URI) [RFC3986] so that they can be persistently and
unambiguously referenced. Jobs can also be identified by a
combination of Printer URI and Job ID.
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Some operation elements are encoded twice, once as the request-target
on the HTTP request-line and a second time as a REQUIRED operation
attribute in the application/ipp entity. These attributes are the
target for the operation and are called "printer-uri" and "job-uri".
Note: The target URI is included twice in an operation referencing
the same IPP object, but the two URIs can be different. For example,
the HTTP request-target can be relative while the IPP request URI is
absolute.
HTTP allows Clients to generate and send a relative URI rather than
an absolute URI. A relative URI identifies a resource with the scope
of the HTTP server but does not include scheme, host, or port. The
following statements characterize how URIs are used in the mapping of
IPP onto HTTP:
1. Although potentially redundant, a Client MUST supply the target
of the operation both as an operation attribute and as a URI at
the HTTP layer. The rationale for this decision is to maintain a
consistent set of rules for mapping "application/ipp" to possibly
many communication layers, even where URIs are not used as the
addressing mechanism in the transport layer.
2. Even though these two URIs might not be literally identical (one
being relative and the other being absolute), they MUST both
reference the same IPP object.
3. The URI in the HTTP layer is either relative or absolute and is
used by the HTTP server to route the HTTP request to the correct
resource relative to that HTTP server.
4. Once the HTTP server resource begins to process the HTTP request,
it can get the reference to the appropriate IPP Printer object
from either the HTTP URI (using to the context of the HTTP server
for relative URIs) or from the URI within the operation request;
the choice is up to the implementation.
5. HTTP URIs can be relative or absolute, but the target URI in the
IPP operation attribute MUST be an absolute URI.
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5. IPP URI Schemes
The IPP URI schemes are 'ipp' [RFC3510] and 'ipps' [RFC7472].
Clients and Printers MUST support the ipp-URI value in the following
IPP attributes:
o Job attributes:
* job-uri
* job-printer-uri
o Printer attributes:
* printer-uri-supported
o Operation attributes:
* job-uri
* printer-uri
Each of the above attributes identifies a Printer or Job. The
ipp-URI and ipps-URI are intended as the value of the attributes in
this list. All of these attributes have a syntax type of 'uri', but
there are attributes with a syntax type of 'uri' that do not use the
'ipp' scheme, e.g., "job-more-info".
If a Printer registers its URI with a directory service, the Printer
MUST register an ipp-URI or ipps-URI.
When a Client sends a request, it MUST convert a target ipp-URI to a
target http-URL (or ipps-URI to a target https-URI) for the HTTP
layer according to the following steps:
1. change the 'ipp' scheme to 'http' or 'ipps' scheme to 'https';
and
2. add an explicit port 631 if the ipp-URL or ipps-URL does not
contain an explicit port. Note that port 631 is the IANA-
assigned well-known port for the 'ipp' and 'ipps' schemes.
The Client MUST use the target http-URL or https-URL in both the HTTP
request-line and HTTP headers, as specified by HTTP [RFC7230].
However, the Client MUST use the target ipp-URI or ipps-URI for the
value of the "printer-uri" or "job-uri" operation attribute within
the application/ipp body of the request. The server MUST use the
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ipp-URI or ipps-URI for the value of the "printer-uri", "job-uri", or
"printer-uri-supported" attributes within the application/ipp body of
the response.
For example, when an IPP Client sends a request directly, i.e., no
proxy, to an ipp-URI "ipp://printer.example.com/ipp/print/myqueue",
it opens a TCP connection to port 631 (the IPP implicit port) on the
host "printer.example.com" and sends the following data:
POST /ipp/print/myqueue HTTP/1.1
Host: printer.example.com:631
Content-type: application/ipp
Transfer-Encoding: chunked
...
"printer-uri" 'ipp://printer.example.com/ipp/print/myqueue'
(encoded in application/ipp message body)
...
Figure 11: Direct IPP Request
As another example, when an IPP Client sends the same request as
above via a proxy "myproxy.example.com", it opens a TCP connection to
the proxy port 8080 on the proxy host "myproxy.example.com" and sends
the following data:
POST http://printer.example.com:631/ipp/print/myqueue HTTP/1.1
Host: printer.example.com:631
Content-type: application/ipp
Transfer-Encoding: chunked
...
"printer-uri" 'ipp://printer.example.com/ipp/print/myqueue'
(encoded in application/ipp message body)
...
Figure 12: Proxied IPP Request
The proxy then connects to the IPP origin server with headers that
are the same as the "no-proxy" example above.
6. IANA Considerations
The IANA-PRINTER-MIB [RFC3805] has been updated to reference this
document; the current version is available from
<http://www.iana.org>.
See the IANA Considerations in the document "Internet Printing
Protocol/1.1: Model and Semantics" [RFC8011] for information on IANA
considerations for IPP extensions. IANA has updated the existing
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'application/ipp' media type registration (whose contents are defined
in Section 3 "Encoding of the Operation Layer") with the following
information.
Type name: application
Subtype name: ipp
Required parameters: N/A
Optional parameters: N/A
Encoding considerations: IPP requests/responses MAY contain long
lines and ALWAYS contain binary data (for example, attribute value
lengths).
Security considerations: IPP requests/responses do not introduce any
security risks not already inherent in the underlying transport
protocols. Protocol mixed-version interworking rules in [RFC8011] as
well as protocol-encoding rules in this document are complete and
unambiguous. See also the security considerations in this document
and [RFC8011].
Interoperability considerations: IPP requests (generated by Clients)
and responses (generated by servers) MUST comply with all conformance
requirements imposed by the normative specifications [RFC8011] and
this document. Protocol-encoding rules specified in RFC 8010 are
comprehensive so that interoperability between conforming
implementations is guaranteed (although support for specific optional
features is not ensured). Both the "charset" and "natural-language"
of all IPP attribute values that are a LOCALIZED-STRING are explicit
within IPP requests/responses (without recourse to any external
information in HTTP, SMTP, or other message transport headers).
Published specifications: RFCs 8010 and 8011
Applications that use this media type: Internet Printing Protocol
(IPP) print clients and print servers that communicate using HTTP/
HTTPS or other transport protocols. Messages of type "application/
ipp" are self-contained and transport independent, including
"charset" and "natural-language" context for any LOCALIZED-STRING
value.
Fragment identifier considerations: N/A
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Additional information:
Deprecated alias names for this type: N/A
Magic number(s): N/A
File extension(s): N/A
Macintosh file type code(s): N/A
Person & email address to contact for further information:
ISTO PWG IPP Workgroup <ipp@pwg.org>
Intended usage: COMMON
Restrictions on usage: N/A
Author: ISTO PWG IPP Workgroup <ipp@pwg.org>
Change controller: ISTO PWG IPP Workgroup <ipp@pwg.org>
Provisional registration? (standards tree only): No
7. Internationalization Considerations
See the section on "Internationalization Considerations" in the
document "Internet Printing Protocol/1.1: Model and Semantics"
[RFC8011] for information on internationalization. This document
adds no additional issues.
8. Security Considerations
The IPP Model and Semantics document [RFC8011] discusses high-level
security requirements (Client Authentication, Server Authentication,
and Operation Privacy). Client Authentication is the mechanism by
which the Client proves its identity to the server in a secure
manner. Server Authentication is the mechanism by which the server
proves its identity to the Client in a secure manner. Operation
Privacy is defined as a mechanism for protecting operations from
eavesdropping.
Message Integrity is addressed in the document "Internet Printing
Protocol (IPP) over HTTPS Transport Binding and the 'ipps' URI
Scheme" [RFC7472].
8.1. Security Conformance Requirements
This section defines the security requirements for IPP Clients and
IPP objects.
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8.1.1. Digest Authentication
IPP Clients and Printers SHOULD support Digest Authentication
[RFC7616]. Use of the Message Integrity feature (qop="auth-int") is
OPTIONAL.
Note: Previous versions of this specification required support for
the MD5 algorithms; however, [RFC7616] makes SHA2-256 mandatory to
implement and deprecates MD5, only allowing its use for backwards
compatibility reasons. IPP implementations that support Digest
Authentication MUST support SHA2-256 and SHOULD support MD5 for
backwards compatibility.
Note: The reason that IPP Clients and Printers SHOULD (rather than
MUST) support Digest Authentication is that there is a certain class
of Output Devices where it does not make sense. Specifically, a low-
end device with limited ROM space and low paper throughput may not
need Client Authentication. This class of device typically requires
firmware designers to make trade-offs between protocols and
functionality to arrive at the lowest-cost solution possible.
Factored into the designer's decisions is not just the size of the
code, but also the testing, maintenance, usefulness, and time-to-
market impact for each feature delivered to the customer. Forcing
such low-end devices to provide security in order to claim IPP/1.1
conformance would not make business sense. Print devices that have
high-volume throughput and have available ROM space will typically
provide support for Client Authentication that safeguards the device
from unauthorized access because these devices are prone to a high
loss of consumables and paper if unauthorized access occurs.
8.1.2. Transport Layer Security (TLS)
IPP Clients and Printers SHOULD support Transport Layer Security
(TLS) [RFC5246] [RFC7525] for Server Authentication and Operation
Privacy. IPP Printers MAY also support TLS for Client
Authentication. IPP Clients and Printers MAY support Basic
Authentication [RFC7617] for User Authentication if the channel is
secure, e.g., IPP over HTTPS [RFC7472]. IPP Clients and Printers
SHOULD NOT support Basic Authentication over insecure channels.
The IPP Model and Semantics document [RFC8011] defines two Printer
attributes ("uri-authentication-supported" and "uri-security-
supported") that the Client can use to discover the security policy
of a Printer. That document also outlines IPP-specific security
considerations and is the primary reference for security implications
with regard to the IPP itself.
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Note: Because previous versions of this specification did not require
TLS support, this version cannot require it for IPP/1.1. However,
since printing often involves a great deal of sensitive or private
information (medical reports, performance reviews, banking
information, etc.) and network monitoring is pervasive ([RFC7258]),
implementors are strongly encouraged to include TLS support.
Note: Because IPP Printers typically use self-signed X.509
certificates, IPP Clients SHOULD support Trust On First Use (defined
in [RFC7435]) in addition to traditional X.509 certificate
validation.
8.2. Using IPP with TLS
IPP uses the "Upgrading to TLS Within HTTP/1.1" mechanism [RFC2817]
for 'ipp' URIs. The Client requests a secure TLS connection by using
the HTTP "Upgrade" header while the server agrees in the HTTP
response. The switch to TLS occurs either because the server grants
the Client's request to upgrade to TLS or a server asks to switch to
TLS in its response. Secure communication begins with a server's
response to switch to TLS.
IPP uses the "HTTPS: HTTP over TLS" mechanism [RFC2818] for 'ipps'
URIs. The Client and server negotiate a secure TLS connection
immediately and unconditionally.
9. Interoperability with Other IPP Versions
It is beyond the scope of this specification to mandate conformance
with versions of IPP other than 1.1. IPP was deliberately designed,
however, to make supporting other versions easy. IPP objects
(Printers, Jobs, etc.) SHOULD:
o understand any valid request whose major "version-number" is
greater than 0; and
o respond appropriately with a response containing the same
"version-number" parameter value used by the Client in the request
(if the Client-supplied "version-number" is supported) or the
highest "version-number" supported by the Printer (if the Client-
supplied "version-number" is not supported).
IPP Clients SHOULD:
o understand any valid response whose major "version-number" is
greater than 0.
Sweet & McDonald Standards Track [Page 33]
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9.1. The "version-number" Parameter
The following are rules regarding the "version-number" parameter (see
Section 3.3):
1. Clients MUST send requests containing a "version-number"
parameter with the highest supported value, e.g., '1.1', '2.0',
etc., and SHOULD try supplying alternate version numbers if they
receive a 'server-error-version-not-supported' error return in a
response. For example, if a Client sends an IPP/2.0 request that
is rejected with the 'server-error-version-not-supported' error
and an IPP/1.1 "version-number", it SHOULD retry by sending an
IPP/1.1 request.
2. IPP objects (Printers, Jobs, etc.) MUST accept requests
containing a "version-number" parameter with a '1.1' value (or
reject the request for reasons other than 'server-error-version-
not-supported').
3. IPP objects SHOULD either accept requests whose major version is
greater than 0 or reject such requests with the 'server-error-
version-not-supported' status-code. See Section 4.1.8 of
[RFC8011].
4. In any case, security MUST NOT be compromised when a Client
supplies a lower "version-number" parameter in a request. For
example, if an IPP/2.0 conforming Printer accepts version '1.1'
requests and is configured to enforce Digest Authentication, it
MUST do the same for a version '1.1' request.
9.2. Security and URI Schemes
The following are rules regarding security, the "version-number"
parameter, and the URI scheme supplied in target attributes and
responses:
1. When a Client supplies a request, the "printer-uri" or "job-uri"
target operation attribute MUST have the same scheme as that
indicated in one of the values of the "printer-uri-supported"
Printer attribute.
2. When the Printer returns the "job-printer-uri" or "job-uri" Job
Description attributes, it SHOULD return the same scheme ('ipp',
'ipps', etc.) that the Client supplied in the "printer-uri" or
"job-uri" target operation attributes in the Get-Job-Attributes
or Get-Jobs request, rather than the scheme used when the Job was
created. However, when a Client requests Job attributes using
the Get-Job-Attributes or Get-Jobs operations, the Jobs and Job
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attributes that the Printer returns depends on: (1) the security
in effect when the Job was created, (2) the security in effect in
the query request, and (3) the security policy in force.
3. The Printer MUST enforce its security and privacy policies based
on the owner of the IPP object and the URI scheme and/or
credentials supplied by the Client in the current request.
10. Changes since RFC 2910
The following changes have been made since the publication of
RFC 2910:
o Added references to current IPP extension specifications.
o Added optional support for HTTP/2.
o Added collection attribute syntax from RFC 3382.
o Fixed typographical errors.
o Now reference TLS/1.2 and no longer mandate the TLS/1.0 MTI
ciphersuites.
o Updated all references.
o Updated document organization to follow current style.
o Updated example ipp: URIs to follow guidelines in RFC 7472.
o Updated version compatibility for all versions of IPP.
o Updated HTTP Digest Authentication to optional for Clients.
o Removed references to (Experimental) IPP/1.0 and usage of
http:/https: URLs.
Sweet & McDonald Standards Track [Page 35]
RFC 8010 IPP/1.1: Encoding and Transport January 2017
11. References
11.1. Normative References
[PWG5100.12]
Sweet, M. and I. McDonald, "IPP Version 2.0, 2.1, and
2.2", October 2015, <http://ftp.pwg.org/pub/pwg/standards/
std-ipp20-20151030-5100.12.pdf>.
[RFC20] Cerf, V., "ASCII format for network interchange", STD 80,
RFC 20, DOI 10.17487/RFC20, October 1969,
<http://www.rfc-editor.org/info/rfc20>.
[RFC793] Postel, J., "Transmission Control Protocol", STD 7,
RFC 793, DOI 10.17487/RFC793, September 1981,
<http://www.rfc-editor.org/info/rfc793>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC2579] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Textual Conventions for SMIv2",
STD 58, RFC 2579, DOI 10.17487/RFC2579, April 1999,
<http://www.rfc-editor.org/info/rfc2579>.
[RFC2817] Khare, R. and S. Lawrence, "Upgrading to TLS Within
HTTP/1.1", RFC 2817, DOI 10.17487/RFC2817, May 2000,
<http://www.rfc-editor.org/info/rfc2817>.
[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818,
DOI 10.17487/RFC2818, May 2000,
<http://www.rfc-editor.org/info/rfc2818>.
[RFC2978] Freed, N. and J. Postel, "IANA Charset Registration
Procedures", BCP 19, RFC 2978, DOI 10.17487/RFC2978,
October 2000, <http://www.rfc-editor.org/info/rfc2978>.
[RFC3510] Herriot, R. and I. McDonald, "Internet Printing
Protocol/1.1: IPP URL Scheme", RFC 3510,
DOI 10.17487/RFC3510, April 2003,
<http://www.rfc-editor.org/info/rfc3510>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
2003, <http://www.rfc-editor.org/info/rfc3629>.
Sweet & McDonald Standards Track [Page 36]
RFC 8010 IPP/1.1: Encoding and Transport January 2017
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<http://www.rfc-editor.org/info/rfc3986>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
<http://www.rfc-editor.org/info/rfc5234>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
<http://www.rfc-editor.org/info/rfc5246>.
[RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, DOI 10.17487/RFC7230, June 2014,
<http://www.rfc-editor.org/info/rfc7230>.
[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
DOI 10.17487/RFC7231, June 2014,
<http://www.rfc-editor.org/info/rfc7231>.
[RFC7232] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Conditional Requests", RFC 7232,
DOI 10.17487/RFC7232, June 2014,
<http://www.rfc-editor.org/info/rfc7232>.
[RFC7234] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching",
RFC 7234, DOI 10.17487/RFC7234, June 2014,
<http://www.rfc-editor.org/info/rfc7234>.
[RFC7235] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Authentication", RFC 7235,
DOI 10.17487/RFC7235, June 2014,
<http://www.rfc-editor.org/info/rfc7235>.
[RFC7472] McDonald, I. and M. Sweet, "Internet Printing Protocol
(IPP) over HTTPS Transport Binding and the 'ipps' URI
Scheme", RFC 7472, DOI 10.17487/RFC7472, March 2015,
<http://www.rfc-editor.org/info/rfc7472>.
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RFC 8010 IPP/1.1: Encoding and Transport January 2017
[RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext
Transfer Protocol Version 2 (HTTP/2)", RFC 7540,
DOI 10.17487/RFC7540, May 2015,
<http://www.rfc-editor.org/info/rfc7540>.
[RFC7541] Peon, R. and H. Ruellan, "HPACK: Header Compression for
HTTP/2", RFC 7541, DOI 10.17487/RFC7541, May 2015,
<http://www.rfc-editor.org/info/rfc7541>.
[RFC7616] Shekh-Yusef, R., Ed., Ahrens, D., and S. Bremer, "HTTP
Digest Access Authentication", RFC 7616,
DOI 10.17487/RFC7616, September 2015,
<http://www.rfc-editor.org/info/rfc7616>.
[RFC7617] Reschke, J., "The 'Basic' HTTP Authentication Scheme",
RFC 7617, DOI 10.17487/RFC7617, September 2015,
<http://www.rfc-editor.org/info/rfc7617>.
[RFC8011] Sweet, M. and I. McDonald, "Internet Printing
Protocol/1.1: Model and Semantics", RFC 8011,
DOI 10.17487/RFC8011, January 2017,
<http://www.rfc-editor.org/info/rfc8011>.
11.2. Informative References
[IANA-IPP] IANA, "Internet Printing Protocol (IPP) Registry",
<http://www.iana.org/assignments/ipp-registrations/>.
[PWG5100.3]
Ocke, K. and T. Hastings, "Internet Printing Protocol
(IPP): Production Printing Attributes - Set1", Candidate
Standard 5100.3-2001, February 2001,
<http://ftp.pwg.org/pub/pwg/candidates/
cs-ippprodprint10-20010212-5100.3.pdf>.
[RFC1179] McLaughlin, L., "Line printer daemon protocol", RFC 1179,
DOI 10.17487/RFC1179, August 1990,
<http://www.rfc-editor.org/info/rfc1179>.
[RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an
Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May
2014, <http://www.rfc-editor.org/info/rfc7258>.
[RFC7435] Dukhovni, V., "Opportunistic Security: Some Protection
Most of the Time", RFC 7435, DOI 10.17487/RFC7435,
December 2014, <http://www.rfc-editor.org/info/rfc7435>.
Sweet & McDonald Standards Track [Page 38]
RFC 8010 IPP/1.1: Encoding and Transport January 2017
[RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre,
"Recommendations for Secure Use of Transport Layer
Security (TLS) and Datagram Transport Layer Security
(DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
2015, <http://www.rfc-editor.org/info/rfc7525>.
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Appendix A. Protocol Examples
A.1. Print-Job Request
The following is an example of a Print-Job request with "job-name",
"copies", and "sides" specified. The "ipp-attribute-fidelity"
attribute is set to 'true' so that the print request will fail if the
"copies" or the "sides" attribute is not supported or their values
are not supported.
Octets Symbolic Value Protocol field
0x0101 1.1 version-number
0x0002 Print-Job operation-id
0x00000001 1 request-id
0x01 start operation- operation-
attributes attributes-tag
0x47 charset type value-tag
0x0012 name-length
attributes-charset attributes-charset name
0x0005 value-length
utf-8 UTF-8 value
0x48 natural-language value-tag
type
0x001b name-length
attributes-natural-language attributes-natural- name
language
0x0005 value-length
en-us en-US value
0x45 uri type value-tag
0x000b name-length
printer-uri printer-uri name
0x002c value-length
ipp://printer.example.com/ipp/ printer pinetree value
print/pinetree
0x42 nameWithoutLanguage value-tag
type
0x0008 name-length
job-name job-name name
0x0006 value-length
foobar foobar value
0x22 boolean type value-tag
0x0016 name-length
ipp-attribute-fidelity ipp-attribute- name
fidelity
0x0001 value-length
0x01 true value
0x02 start job-attributes job-attributes-
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tag
0x21 integer type value-tag
0x0006 name-length
copies copies name
0x0004 value-length
0x00000014 20 value
0x44 keyword type value-tag
0x0005 name-length
sides sides name
0x0013 value-length
two-sided-long-edge two-sided-long-edge value
0x03 end-of-attributes end-of-
attributes-tag
%!PDF... <PDF Document> data
A.2. Print-Job Response (Successful)
Here is an example of a successful Print-Job response to the previous
Print-Job request. The Printer supported the "copies" and "sides"
attributes and their supplied values. The status-code returned is
'successful-ok'.
Octets Symbolic Value Protocol field
0x0101 1.1 version-number
0x0000 successful-ok status-code
0x00000001 1 request-id
0x01 start operation- operation-
attributes attributes-tag
0x47 charset type value-tag
0x0012 name-length
attributes-charset attributes-charset name
0x0005 value-length
utf-8 UTF-8 value
0x48 natural-language value-tag
type
0x001b name-length
attributes-natural-language attributes- name
natural-language
0x0005 value-length
en-us en-US value
0x41 textWithoutLanguag value-tag
e type
0x000e name-length
status-message status-message name
0x000d value-length
successful-ok successful-ok value
0x02 start job- job-attributes-
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attributes tag
0x21 integer value-tag
0x0006 name-length
job-id job-id name
0x0004 value-length
147 147 value
0x45 uri type value-tag
0x0007 name-length
job-uri job-uri name
0x0030 value-length
ipp://printer.example.com/ipp/pr job 147 on value
int/pinetree/147 pinetree
0x23 enum type value-tag
0x0009 name-length
job-state job-state name
0x0004 value-length
0x0003 pending value
0x03 end-of-attributes end-of-
attributes-tag
A.3. Print-Job Response (Failure)
Here is an example of an unsuccessful Print-Job response to the
previous Print-Job request. It fails because, in this case, the
Printer does not support the "sides" attribute and because the value
'20' for the "copies" attribute is not supported. Therefore, no Job
is created, and neither a "job-id" nor a "job-uri" operation
attribute is returned. The error code returned is 'client-error-
attributes-or-values-not-supported' (0x040b).
Octets Symbolic Value Protocol
field
0x0101 1.1 version-
number
0x040b client-error-attributes-or- status-code
values-not-supported
0x00000001 1 request-id
0x01 start operation-attributes operation-
attributes
tag
0x47 charset type value-tag
0x0012 name-length
attributes-charset attributes-charset name
0x0005 value-length
utf-8 UTF-8 value
0x48 natural-language type value-tag
0x001b name-length
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attributes-natural-language attributes-natural-language name
0x0005 value-length
en-us en-US value
0x41 textWithoutLanguage type value-tag
0x000e name-length
status-message status-message name
0x002f value-length
client-error-attributes-or- client-error-attributes-or- value
values-not-supported values-not-supported
0x05 start unsupported- unsupported-
attributes attributes
tag
0x21 integer type value-tag
0x0006 name-length
copies copies name
0x0004 value-length
0x00000014 20 value
0x10 unsupported (type) value-tag
0x0005 name-length
sides sides name
0x0000 value-length
0x03 end-of-attributes end-of-
attributes-
tag
A.4. Print-Job Response (Success with Attributes Ignored)
Here is an example of a successful Print-Job response to a Print-Job
request like the previous Print-Job request, except that the value of
"ipp-attribute-fidelity" is 'false'. The print request succeeds,
even though, in this case, the Printer supports neither the "sides"
attribute nor the value '20' for the "copies" attribute. Therefore,
a Job is created and both a "job-id" and a "job-uri" operation
attribute are returned. The unsupported attributes are also returned
in an Unsupported Attributes group. The error code returned is
'successful-ok-ignored-or-substituted-attributes' (0x0001).
Octets Symbolic Value Protocol field
0x0101 1.1 version-number
0x0001 successful-ok-ignored-or- status-code
substituted-attributes
0x00000001 1 request-id
0x01 start operation-attributes operation-
attributes-tag
0x47 charset type value-tag
0x0012 name-length
attributes-charset attributes-charset name
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0x0005 value-length
utf-8 UTF-8 value
0x48 natural-language type value-tag
0x001b name-length
attributes-natural- attributes-natural-language name
language
0x0005 value-length
en-us en-US value
0x41 textWithoutLanguage type value-tag
0x000e name-length
status-message status-message name
0x002f value-length
successful-ok-ignored-or- successful-ok-ignored-or- value
substituted-attributes substituted-attributes
0x05 start unsupported- unsupported-
attributes attributes tag
0x21 integer type value-tag
0x0006 name-length
copies copies name
0x0004 value-length
0x00000014 20 value
0x10 unsupported (type) value-tag
0x0005 name-length
sides sides name
0x0000 value-length
0x02 start job-attributes job-
attributes-tag
0x21 integer value-tag
0x0006 name-length
job-id job-id name
0x0004 value-length
147 147 value
0x45 uri type value-tag
0x0007 name-length
job-uri job-uri name
0x0030 value-length
ipp://printer.example.com/ job 147 on pinetree value
ipp/print/pinetree/147
0x23 enum type value-tag
0x0009 name-length
job-state job-state name
0x0004 value-length
0x0003 pending value
0x03 end-of-attributes end-of-
attributes-tag
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A.5. Print-URI Request
The following is an example of Print-URI request with "copies" and
"job-name" parameters:
Octets Symbolic Value Protocol field
0x0101 1.1 version-number
0x0003 Print-URI operation-id
0x00000001 1 request-id
0x01 start operation- operation-
attributes attributes-tag
0x47 charset type value-tag
0x0012 name-length
attributes-charset attributes-charset name
0x0005 value-length
utf-8 UTF-8 value
0x48 natural-language value-tag
type
0x001b name-length
attributes-natural-language attributes-natural- name
language
0x0005 value-length
en-us en-US value
0x45 uri type value-tag
0x000b name-length
printer-uri printer-uri name
0x002c value-length
ipp://printer.example.com/ipp/ printer pinetree value
print/pinetree
0x45 uri type value-tag
0x000c name-length
document-uri document-uri name
0x0019 value-length
ftp://foo.example.com/foo ftp://foo.example.co value
m/foo
0x42 nameWithoutLanguage value-tag
type
0x0008 name-length
job-name job-name name
0x0006 value-length
foobar foobar value
0x02 start job-attributes job-attributes-
tag
0x21 integer type value-tag
0x0006 name-length
copies copies name
0x0004 value-length
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0x00000001 1 value
0x03 end-of-attributes end-of-
attributes-tag
A.6. Create-Job Request
The following is an example of Create-Job request with no parameters
and no attributes:
Octets Symbolic Value Protocol field
0x0101 1.1 version-number
0x0005 Create-Job operation-id
0x00000001 1 request-id
0x01 start operation- operation-
attributes attributes-tag
0x47 charset type value-tag
0x0012 name-length
attributes-charset attributes-charset name
0x0005 value-length
utf-8 UTF-8 value
0x48 natural-language value-tag
type
0x001b name-length
attributes-natural-language attributes-natural- name
language
0x0005 value-length
en-us en-US value
0x45 uri type value-tag
0x000b name-length
printer-uri printer-uri name
0x002c value-length
ipp://printer.example.com/ipp/ printer pinetree value
print/pinetree
0x03 end-of-attributes end-of-
attributes-tag
A.7. Create-Job Request with Collection Attributes
The following is an example of Create-Job request with the "media-
col" collection attribute [PWG5100.3] with the value "media-
size={x-dimension=21000 y-dimension=29700} media-type='stationery'":
Octets Symbolic Value Protocol field
0x0101 1.1 version-number
0x0005 Create-Job operation-id
0x00000001 1 request-id
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0x01 start operation- operation-
attributes attributes-tag
0x47 charset type value-tag
0x0012 name-length
attributes-charset attributes-charset name
0x0005 value-length
utf-8 UTF-8 value
0x48 natural-language value-tag
type
0x001b name-length
attributes-natural-language attributes-natural- name
language
0x0005 value-length
en-us en-US value
0x45 uri type value-tag
0x000b name-length
printer-uri printer-uri name
0x002c value-length
ipp://printer.example.com/ipp/ printer pinetree value
print/pinetree
0x34 begCollection value-tag
0x0009 9 name-length
media-col media-col name
0x0000 0 value-length
0x4a memberAttrName value-tag
0x0000 0 name-length
0x000a 10 value-length
media-size media-size value (member-
name)
0x34 begCollection member-value-tag
0x0000 0 name-length
0x0000 0 member-value-
length
0x4a memberAttrName value-tag
0x0000 0 name-length
0x000b 11 value-length
x-dimension x-dimension value (member-
name)
0x21 integer member-value-tag
0x0000 0 name-length
0x0004 4 member-value-
length
0x00005208 21000 member-value
0x4a memberAttrName value-tag
0x0000 0 name-length
0x000b 11 value-length
y-dimension y-dimension value (member-
name)
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0x21 integer member-value-tag
0x0000 0 name-length
0x0004 4 member-value-
length
0x00007404 29700 member-value
0x37 endCollection end-value-tag
0x0000 0 end-name-length
0x0000 0 end-value-length
0x4a memberAttrName value-tag
0x0000 0 name-length
0x000a 10 value-length
media-type media-type value (member-
name)
0x44 keyword member-value-tag
0x0000 0 name-length
0x000a 10 member-value-
length
stationery stationery member-value
0x37 endCollection end-value-tag
0x0000 0 end-name-length
0x0000 0 end-value-length
0x03 end-of-attributes end-of-
attributes-tag
A.8. Get-Jobs Request
The following is an example of Get-Jobs request with parameters but
no attributes:
Octets Symbolic Value Protocol field
0x0101 1.1 version-number
0x000a Get-Jobs operation-id
0x0000007b 123 request-id
0x01 start operation- operation-
attributes attributes-tag
0x47 charset type value-tag
0x0012 name-length
attributes-charset attributes-charset name
0x0005 value-length
utf-8 UTF-8 value
0x48 natural-language value-tag
type
0x001b name-length
attributes-natural-language attributes-natural- name
language
0x0005 value-length
en-us en-US value
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0x45 uri type value-tag
0x000b name-length
printer-uri printer-uri name
0x002c value-length
ipp://printer.example.com/ipp/ printer pinetree value
print/pinetree
0x21 integer type value-tag
0x0005 name-length
limit limit name
0x0004 value-length
0x00000032 50 value
0x44 keyword type value-tag
0x0014 name-length
requested-attributes requested-attributes name
0x0006 value-length
job-id job-id value
0x44 keyword type value-tag
0x0000 additional value name-length
0x0008 value-length
job-name job-name value
0x44 keyword type value-tag
0x0000 additional value name-length
0x000f value-length
document-format document-format value
0x03 end-of-attributes end-of-
attributes-tag
A.9. Get-Jobs Response
The following is an example of a Get-Jobs response from a previous
request with three Jobs. The Printer returns no information about
the second Job (because of security reasons):
Octets Symbolic Value Protocol field
0x0101 1.1 version-number
0x0000 successful-ok status-code
0x0000007b 123 request-id (echoed
back)
0x01 start operation- operation-attributes-
attributes tag
0x47 charset type value-tag
0x0012 name-length
attributes-charset attributes-charset name
0x0005 value-length
utf-8 UTF-8 value
0x48 natural-language type value-tag
0x001b name-length
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RFC 8010 IPP/1.1: Encoding and Transport January 2017
attributes-natural- attributes-natural- name
language language
0x0005 value-length
en-us en-US value
0x41 textWithoutLanguage value-tag
type
0x000e name-length
status-message status-message name
0x000d value-length
successful-ok successful-ok value
0x02 start job-attributes job-attributes-tag
(1st object)
0x21 integer type value-tag
0x0006 name-length
job-id job-id name
0x0004 value-length
147 147 value
0x36 nameWithLanguage value-tag
0x0008 name-length
job-name job-name name
0x000c value-length
0x0005 sub-value-length
fr-ca fr-CA value
0x0003 sub-value-length
fou fou name
0x02 start job-attributes job-attributes-tag
(2nd object)
0x02 start job-attributes job-attributes-tag
(3rd object)
0x21 integer type value-tag
0x0006 name-length
job-id job-id name
0x0004 value-length
148 149 value
0x36 nameWithLanguage value-tag
0x0008 name-length
job-name job-name name
0x0012 value-length
0x0005 sub-value-length
de-CH de-CH value
0x0009 sub-value-length
isch guet isch guet name
0x03 end-of-attributes end-of-attributes-tag
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RFC 8010 IPP/1.1: Encoding and Transport January 2017
Acknowledgements
The authors would like to acknowledge the following individuals for
their contributions to the original IPP/1.1 specifications:
Sylvan Butler, Roger deBry, Tom Hastings, Robert Herriot (the
original editor of RFC 2910), Paul Moore, Kirk Ocke, Randy Turner,
John Wenn, and Peter Zehler.
Authors' Addresses
Michael Sweet
Apple Inc.
1 Infinite Loop
MS 111-HOMC
Cupertino, CA 95014
United States of America
Email: msweet@apple.com
Ira McDonald
High North, Inc.
PO Box 221
Grand Marais, MI 49839
United States of America
Phone: +1 906-494-2434
Email: blueroofmusic@gmail.com
Sweet & McDonald Standards Track [Page 51]
=========================================================================
Internet Engineering Task Force (IETF) M. Sweet
Request for Comments: 8011 Apple Inc.
Obsoletes: 2911, 3381, 3382 I. McDonald
Category: Standards Track High North, Inc.
ISSN: 2070-1721 January 2017
Internet Printing Protocol/1.1: Model and Semantics
Abstract
The Internet Printing Protocol (IPP) is an application-level protocol
for distributed printing using Internet tools and technologies. This
document describes a simplified model consisting of abstract objects,
attributes, and operations that is independent of encoding and
transport. The model consists of several objects, including Printers
and Jobs. Jobs optionally support multiple Documents.
IPP semantics allow End Users and Operators to query Printer
capabilities; submit Print Jobs; inquire about the status of Print
Jobs and Printers; and cancel, hold, and release Print Jobs. IPP
semantics also allow Operators to pause and resume Jobs and Printers.
Security, internationalization, and directory issues are also
addressed by the model and semantics. The IPP message encoding and
transport are described in "Internet Printing Protocol/1.1: Encoding
and Transport" (RFC 8010).
This document obsoletes RFCs 2911, 3381, and 3382.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8011.
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RFC 8011 IPP/1.1: Model and Semantics January 2017
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
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Table of Contents
1. Introduction ....................................................9
1.1. Simplified Printing Model .................................12
2. Conventions Used in This Document ..............................15
2.1. Requirements Language .....................................15
2.2. Printing Terminology ......................................15
2.3. Model Terminology .........................................16
2.3.1. Administrator ......................................16
2.3.2. Attributes .........................................16
2.3.2.1. Attribute Group Name ......................16
2.3.2.2. Attribute Name ............................16
2.3.2.3. Attribute Syntax ..........................16
2.3.2.4. Attribute Value ...........................17
2.3.3. End User ...........................................17
2.3.4. Impression .........................................17
2.3.5. Input Page .........................................17
2.3.6. Job Creation Operation .............................17
2.3.7. Keyword ............................................17
2.3.8. Media Sheet ........................................18
2.3.9. Operator ...........................................18
2.3.10. Set ...............................................18
2.3.11. Support of Attributes .............................18
2.3.12. Terminating State .................................21
2.4. Abbreviations .............................................21
3. IPP Objects ....................................................22
3.1. Printer Object ............................................22
3.2. Job Object ................................................25
3.3. Object Relationships ......................................25
3.4. Object Identity ...........................................26
4. IPP Operations .................................................29
4.1. Common Semantics ..........................................30
4.1.1. Required Parameters ................................30
4.1.2. Operation IDs and Request IDs ......................31
4.1.3. Attributes .........................................31
4.1.4. Character Set and Natural Language
Operation Attributes ...............................33
4.1.4.1. Request Operation Attributes ..............34
4.1.4.2. Response Operation Attributes .............38
4.1.5. Operation Targets ..................................39
4.1.6. Operation Response Status-Code Values and
Status Messages ....................................41
4.1.6.1. "status-code" (type2 enum) ................41
4.1.6.2. "status-message" (text(255)) ..............42
4.1.6.3. "detailed-status-message" (text(MAX)) .....43
4.1.6.4. "document-access-error" (text(MAX)) .......43
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4.1.7. Unsupported Attributes .............................44
4.1.8. Versions ...........................................45
4.1.9. Job Creation Operations ............................48
4.2. Printer Operations ........................................50
4.2.1. Print-Job Operation ................................51
4.2.1.1. Print-Job Request .........................51
4.2.1.2. Print-Job Response ........................56
4.2.2. Print-URI Operation ................................58
4.2.3. Validate-Job Operation .............................59
4.2.4. Create-Job Operation ...............................59
4.2.5. Get-Printer-Attributes Operation ...................60
4.2.5.1. Get-Printer-Attributes Request ............61
4.2.5.2. Get-Printer-Attributes Response ...........63
4.2.6. Get-Jobs Operation .................................64
4.2.6.1. Get-Jobs Request ..........................65
4.2.6.2. Get-Jobs Response .........................66
4.2.7. Pause-Printer Operation ............................68
4.2.7.1. Pause-Printer Request .....................71
4.2.7.2. Pause-Printer Response ....................71
4.2.8. Resume-Printer Operation ...........................72
4.2.9. Purge-Jobs Operation ...............................73
4.3. Job Operations ............................................73
4.3.1. Send-Document Operation ............................74
4.3.1.1. Send-Document Request .....................75
4.3.1.2. Send-Document Response ....................77
4.3.2. Send-URI Operation .................................78
4.3.3. Cancel-Job Operation ...............................78
4.3.3.1. Cancel-Job Request ........................80
4.3.3.2. Cancel-Job Response .......................81
4.3.4. Get-Job-Attributes Operation .......................81
4.3.4.1. Get-Job-Attributes Request ................82
4.3.4.2. Get-Job-Attributes Response ...............83
4.3.5. Hold-Job Operation .................................84
4.3.5.1. Hold-Job Request ..........................86
4.3.5.2. Hold-Job Response .........................87
4.3.6. Release-Job Operation ..............................87
4.3.7. Restart-Job Operation ..............................89
4.3.7.1. Restart-Job Request .......................91
4.3.7.2. Restart-Job Response ......................92
5. Object Attributes ..............................................92
5.1. Attribute Syntaxes ........................................92
5.1.1. Out-of-Band Values - 'unknown',
'unsupported', and 'no-value' ......................93
5.1.2. 'text' .............................................93
5.1.2.1. 'textWithoutLanguage' .....................94
5.1.2.2. 'textWithLanguage' ........................94
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5.1.3. 'name' .............................................95
5.1.3.1. 'nameWithoutLanguage' .....................96
5.1.3.2. 'nameWithLanguage' ........................96
5.1.3.3. Matching 'name' Attribute Values ..........97
5.1.4. 'keyword' ..........................................98
5.1.5. 'enum' .............................................99
5.1.6. 'uri' .............................................100
5.1.7. 'uriScheme' .......................................100
5.1.8. 'charset' .........................................101
5.1.9. 'naturalLanguage' .................................102
5.1.10. 'mimeMediaType' ..................................102
5.1.10.1. 'application/octet-stream' -
Auto-Sensing the Document Format ........103
5.1.11. 'octetString' ....................................104
5.1.12. 'boolean' ........................................104
5.1.13. 'integer' ........................................104
5.1.14. 'rangeOfInteger' .................................105
5.1.15. 'dateTime' .......................................105
5.1.16. 'resolution' .....................................105
5.1.17. 'collection' .....................................105
5.1.18. '1setOf X' .......................................106
5.2. Job Template Attributes ..................................106
5.2.1. job-priority (integer(1:100)) .....................109
5.2.2. job-hold-until (type2 keyword | name(MAX)) ........111
5.2.3. job-sheets (type2 keyword | name(MAX)) ............112
5.2.4. multiple-document-handling (type2 keyword) ........113
5.2.5. copies (integer(1:MAX)) ...........................115
5.2.6. finishings (1setOf type2 enum) ....................115
5.2.7. page-ranges (1setOf rangeOfInteger(1:MAX)) ........118
5.2.8. sides (type2 keyword) .............................119
5.2.9. number-up (integer(1:MAX)) ........................120
5.2.10. orientation-requested (type2 enum) ...............120
5.2.11. media (type2 keyword | name(MAX)) ................123
5.2.12. printer-resolution (resolution) ..................124
5.2.13. print-quality (type2 enum) .......................124
5.3. Job Description and Status Attributes ....................124
5.3.1. job-id (integer(1:MAX)) ...........................126
5.3.2. job-uri (uri) .....................................126
5.3.3. job-printer-uri (uri) .............................127
5.3.4. job-more-info (uri) ...............................127
5.3.5. job-name (name(MAX)) ..............................127
5.3.6. job-originating-user-name (name(MAX)) .............128
5.3.7. job-state (type1 enum) ............................128
5.3.7.1. Forwarding Servers .......................132
5.3.7.2. Partitioning of Job States ...............132
5.3.8. job-state-reasons (1setOf type2 keyword) ..........133
5.3.9. job-state-message (text(MAX)) .....................138
5.3.10. job-detailed-status-messages (1setOf text(MAX)) ..139
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5.3.11. job-document-access-errors (1setOf text(MAX)) ....139
5.3.12. number-of-documents (integer(0:MAX)) .............139
5.3.13. output-device-assigned (name(127)) ...............139
5.3.14. Event Time Job Status Attributes .................140
5.3.14.1. time-at-creation (integer(MIN:MAX)) .....140
5.3.14.2. time-at-processing (integer(MIN:MAX)) ...141
5.3.14.3. time-at-completed (integer(MIN:MAX)) ....141
5.3.14.4. job-printer-up-time (integer(1:MAX)) ....141
5.3.14.5. date-time-at-creation
(dateTime|unknown) ......................141
5.3.14.6. date-time-at-processing
(dateTime|unknown|no-value) .............141
5.3.14.7. date-time-at-completed
(dateTime|unknown|no-value) .............141
5.3.15. number-of-intervening-jobs (integer(0:MAX)) ......142
5.3.16. job-message-from-operator (text(127)) ............142
5.3.17. Job Size Attributes ..............................142
5.3.17.1. job-k-octets (integer(0:MAX)) ...........142
5.3.17.2. job-impressions (integer(0:MAX)) ........143
5.3.17.3. job-media-sheets (integer(1:MAX)) .......143
5.3.18. Job Progress Attributes ..........................144
5.3.18.1. job-k-octets-processed
(integer(0:MAX)) ........................144
5.3.18.2. job-impressions-completed
(integer(0:MAX)) ........................144
5.3.18.3. job-media-sheets-completed
(integer(0:MAX)) ........................144
5.3.19. attributes-charset (charset) .....................144
5.3.20. attributes-natural-language (naturalLanguage) ....145
5.4. Printer Description and Status Attributes ................145
5.4.1. printer-uri-supported (1setOf uri) ................147
5.4.2. uri-authentication-supported (1setOf type2
keyword) ..........................................148
5.4.3. uri-security-supported (1setOf type2 keyword) .....149
5.4.4. printer-name (name(127)) ..........................150
5.4.5. printer-location (text(127)) ......................150
5.4.6. printer-info (text(127)) ..........................151
5.4.7. printer-more-info (uri) ...........................151
5.4.8. printer-driver-installer (uri) ....................151
5.4.9. printer-make-and-model (text(127)) ................151
5.4.10. printer-more-info-manufacturer (uri) .............151
5.4.11. printer-state (type1 enum) .......................152
5.4.12. printer-state-reasons (1setOf type2 keyword) .....152
5.4.13. printer-state-message (text(MAX)) ................157
5.4.14. ipp-versions-supported (1setOf type2 keyword) ....157
5.4.15. operations-supported (1setOf type2 enum) .........157
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5.4.16. multiple-document-jobs-supported (boolean) .......159
5.4.17. charset-configured (charset) .....................159
5.4.18. charset-supported (1setOf charset) ...............159
5.4.19. natural-language-configured (naturalLanguage) ....160
5.4.20. generated-natural-language-supported
(1setOf naturalLanguage) .........................160
5.4.21. document-format-default (mimeMediaType) ..........160
5.4.22. document-format-supported (1setOf
mimeMediaType) ...................................161
5.4.23. printer-is-accepting-jobs (boolean) ..............161
5.4.24. queued-job-count (integer(0:MAX)) ................161
5.4.25. printer-message-from-operator (text(127)) ........161
5.4.26. color-supported (boolean) ........................161
5.4.27. reference-uri-schemes-supported (1setOf
uriScheme) .......................................162
5.4.28. pdl-override-supported (type2 keyword) ...........162
5.4.29. printer-up-time (integer(1:MAX)) .................162
5.4.30. printer-current-time (dateTime|unknown) ..........163
5.4.31. multiple-operation-time-out (integer(1:MAX)) .....164
5.4.32. compression-supported (1setOf type2 keyword) .....164
5.4.33. job-k-octets-supported (rangeOfInteger(0:MAX)) ...165
5.4.34. job-impressions-supported
(rangeOfInteger(0:MAX)) ..........................165
5.4.35. job-media-sheets-supported
(rangeOfInteger(1:MAX)) ..........................165
5.4.36. pages-per-minute (integer(0:MAX)) ................165
5.4.37. pages-per-minute-color (integer(0:MAX)) ..........165
6. Conformance ...................................................166
6.1. Client Conformance Requirements ..........................166
6.2. IPP Object Conformance Requirements ......................168
6.2.1. Objects ...........................................168
6.2.2. Operations ........................................168
6.2.3. IPP Object Attributes .............................170
6.2.4. Versions ..........................................170
6.2.5. Extensions ........................................171
6.2.6. Attribute Syntaxes ................................171
6.2.7. Security ..........................................172
6.3. Charset and Natural Language Requirements ................172
7. IANA Considerations ...........................................173
7.1. Object Extensions ........................................174
7.2. Attribute Extensibility ..................................174
7.3. Keyword Extensibility ....................................175
7.4. Enum Extensibility .......................................176
7.5. Attribute Group Extensibility ............................176
7.6. Out-of-Band Attribute Value Extensibility ................176
7.7. Attribute Syntax Extensibility ...........................177
7.8. Operation Extensibility ..................................177
7.9. Status-Code Extensibility ................................178
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8. Internationalization Considerations ...........................179
9. Security Considerations .......................................183
9.1. Security Scenarios .......................................184
9.1.1. Client and Server in the Same Security Domain .....184
9.1.2. Client and Server in Different Security Domains ...184
9.1.3. Print by Reference ................................184
9.2. URIs in Operation, Job, and Printer Attributes ...........185
9.3. URIs for Each Authentication Mechanism ...................185
9.4. Restricted Queries .......................................186
9.5. Operations Performed by Operators and Administrators .....186
9.6. Queries on Jobs Submitted Using Non-IPP Protocols ........186
10. Changes since RFC 2911 .......................................187
11. References ...................................................188
11.1. Normative References ....................................188
11.2. Informative References ..................................194
Appendix A. Formats for IPP Registration Proposals ...............197
A.1. Attribute Registration ....................................197
A.2. type2 'keyword' Attribute Value Registration ..............198
A.3. type2 'enum' Attribute Value Registration .................198
A.4. Operation Registration ....................................199
A.5. Status-Code Registration ..................................199
Appendix B. Status-Code Values and Suggested Status-Code
Messages .............................................200
B.1. Status-Code Values ........................................201
B.1.1. Informational .........................................201
B.1.2. Successful Status-Code Values .........................201
B.1.2.1. successful-ok (0x0000) ............................201
B.1.2.2. successful-ok-ignored-or-substituted-attributes
(0x0001) ..........................................202
B.1.2.3. successful-ok-conflicting-attributes (0x0002) .....202
B.1.3. Redirection Status-Code Values ........................202
B.1.4. Client Error Status-Code Values .......................202
B.1.4.1. client-error-bad-request (0x0400) .................203
B.1.4.2. client-error-forbidden (0x0401) ...................203
B.1.4.3. client-error-not-authenticated (0x0402) ...........203
B.1.4.4. client-error-not-authorized (0x0403) ..............203
B.1.4.5. client-error-not-possible (0x0404) ................203
B.1.4.6. client-error-timeout (0x0405) .....................204
B.1.4.7. client-error-not-found (0x0406) ...................204
B.1.4.8. client-error-gone (0x0407) ........................204
B.1.4.9. client-error-request-entity-too-large (0x0408) ....205
B.1.4.10. client-error-request-value-too-long (0x0409) .....205
B.1.4.11. client-error-document-format-not-supported
(0x040a) .........................................205
B.1.4.12. client-error-attributes-or-values-not-supported
(0x040b) .........................................206
B.1.4.13. client-error-uri-scheme-not-supported (0x040c) ...206
B.1.4.14. client-error-charset-not-supported (0x040d) ......206
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B.1.4.15. client-error-conflicting-attributes (0x040e) .....207
B.1.4.16. client-error-compression-not-supported (0x040f) ..207
B.1.4.17. client-error-compression-error (0x0410) ..........207
B.1.4.18. client-error-document-format-error (0x0411) ......207
B.1.4.19. client-error-document-access-error (0x0412) ......207
B.1.5. Server Error Status-Code Values .......................208
B.1.5.1. server-error-internal-error (0x0500) ..............208
B.1.5.2. server-error-operation-not-supported (0x0501) .....208
B.1.5.3. server-error-service-unavailable (0x0502) .........208
B.1.5.4. server-error-version-not-supported (0x0503) .......209
B.1.5.5. server-error-device-error (0x0504) ................209
B.1.5.6. server-error-temporary-error (0x0505) .............210
B.1.5.7. server-error-not-accepting-jobs (0x0506) ..........210
B.1.5.8. server-error-busy (0x0507) ........................210
B.1.5.9. server-error-job-canceled (0x0508) ................210
B.1.5.10. server-error-multiple-document-jobs-not-supported
(0x0509) .........................................210
B.2. Status-Code Values for IPP Operations .....................211
Appendix C. Processing IPP Attributes ............................213
C.1. Fidelity ..................................................213
C.2. Page Description Language (PDL) Override ..................215
C.3. Using Job Template Attributes during Document Processing ..217
Appendix D. Generic Directory Schema .............................218
Acknowledgements .................................................221
Authors' Addresses ...............................................221
1. Introduction
The Internet Printing Protocol (IPP) is an application-level protocol
for distributed printing using Internet tools and technologies. IPP
version 1.1 (IPP/1.1) focuses primarily on End User functionality
with a few administrative operations included. IPP versions 2.0,
2.1, and 2.2 provide many new operations and are defined separately.
This document is just one of a suite of documents that fully define
IPP. The full set of IETF IPP documents includes:
Design Goals for an Internet Printing Protocol [RFC2567]
Rationale for the Structure of the Model and Protocol for the
Internet Printing Protocol [RFC2568]
Internet Printing Protocol/1.1: Model and Semantics (this
document)
Internet Printing Protocol/1.1: Encoding and Transport [RFC8010]
Internet Printing Protocol/1.1: Implementor's Guide [RFC3196]
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RFC 8011 IPP/1.1: Model and Semantics January 2017
Internet Printing Protocol/1.1: IPP URL Scheme [RFC3510]
Internet Printing Protocol (IPP) over HTTPS Transport Binding and
the 'ipps' URI Scheme [RFC7472]
Internet Printing Protocol (IPP): Requirements for Job, Printer,
and Device Administrative Operations [RFC3239]
Internet Printing Protocol (IPP): Job and Printer Set Operations
[RFC3380]
Internet Printing Protocol (IPP): Job and Printer Administrative
Operations [RFC3998]
Internet Printing Protocol (IPP): Requirements for IPP
Notifications [RFC3997]
Internet Printing Protocol (IPP): Event Notifications and
Subscriptions [RFC3995]
Internet Printing Protocol (IPP): The 'ippget' Delivery Method for
Event Notifications [RFC3996]
Mapping between LPD and IPP Protocols [RFC2569]
Anyone reading these documents for the first time is strongly
encouraged to read the IPP documents in the above order. Additional
IPP specifications have been published by the IEEE-ISTO Printer
Working Group's IPP Workgroup [PWG-IPP-WG]. The following standards
are highly recommended reading:
PWG Media Standardized Names 2.0 (MSN2) [PWG5101.1]
IPP Finishings 2.0 (FIN) [PWG5100.1]
Internet Printing Protocol (IPP): "output-bin" attribute extension
[PWG5100.2]
Internet Printing Protocol (IPP): Production Printing Attributes -
Set 1 [PWG5100.3] (for "media-col" Job Template attribute)
Standard for The Internet Printing Protocol (IPP): Document Object
[PWG5100.5]
Standard for The Internet Printing Protocol (IPP): Page Overrides
[PWG5100.6]
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Standard for The Internet Printing Protocol (IPP): Job Extensions
[PWG5100.7]
Standard for Internet Printing Protocol (IPP): "-actual"
attributes [PWG5100.8]
Internet Printing Protocol (IPP): Printer State Extensions v1.0
[PWG5100.9]
Internet Printing Protocol (IPP): Job and Printer Extensions -
Set 2 (JPS2) [PWG5100.11]
IPP Version 2.0, 2.1, and 2.2 [PWG5100.12]
IPP: Job and Printer Extensions - Set 3 (JPS3) [PWG5100.13]
IPP Everywhere [PWG5100.14]
IPP FaxOut Service [PWG5100.15]
IPP Transaction-Based Printing Extensions [PWG5100.16]
IPP Scan Service (SCAN) [PWG5100.17]
IPP Shared Infrastructure Extensions (INFRA) [PWG5100.18]
IPP Implementor's Guide v2.0 (IG) [PWG5100.19]
This document is organized as follows:
o The rest of Section 1 is an introduction to the IPP simplified
model for distributed printing;
o Section 2 defines the terminology and conventions used within this
document;
o Section 3 introduces the object types covered in this document
with their basic behaviors, attributes, and interactions;
o Section 4 defines the core operations for IPP/1.1. IPP operations
are synchronous -- each operation has both a request and a
response;
o Section 5 defines the core attributes (and their syntaxes) that
are used in the model;
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o Sections 6 and 7 summarize the implementation conformance
requirements for objects that support the protocol and IANA
considerations, respectively;
o Sections 8 and 9 cover the internationalization and security
considerations for IPP; and
o The appendices provide a reference for status-code values,
processing of IPP attributes, and the generic directory schema.
1.1. Simplified Printing Model
In order to achieve its goal of realizing a workable printing
protocol for the Internet, the Internet Printing Protocol (IPP) is
based on a simplified printing model that abstracts the many
components of real-world printing solutions. The Internet is a
distributed computing environment where requesters of print services
(Clients, applications, Printer drivers, etc.) cooperate and interact
with print service providers. This document (sometimes referred to
here as the "Model and Semantics" document) describes a simple,
abstract model for IPP even though the underlying configurations can
be complex "n-tier" client/server systems. An important simplifying
step in the IPP Model is to expose only the key objects and
interfaces required for printing. The model described in this
document does not include features, interfaces, and relationships
that are beyond the scope of IPP/1.1. IPP/1.1 incorporates many of
the relevant ideas and lessons learned from other specification and
development efforts [HTPP] [ISO10175] [LDPA] [P1387.4] [PSIS]
[RFC1179] [SWP]. IPP is heavily influenced by the printing model
introduced in the Document Printing Application (DPA) [ISO10175]
standard. Although DPA specifies both End User and administrative
features, IPP/1.1 focuses primarily on End User functionality with a
few additional OPTIONAL operations for Administrators and Operators.
The IPP Model encapsulates the important components of distributed
printing into the following IPP object types:
o Printer (Section 3.1)
o Job (Section 3.2)
o Document (see [PWG5100.5])
o Subscription (see [RFC3995])
Each object type has an associated set of operations (see Section 4)
and attributes (see Section 5).
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It is important, however, to understand that in real system
implementations (which lie underneath the abstracted IPP Model),
there are other components of a print service that are not explicitly
defined in the IPP Model. The following figure illustrates where IPP
fits with respect to these other components.
+----------------+
| Application |
o + . . . . . . . |
\|/ | Spooler |
/ \ + . . . . . . . | +---------+
End User | Printer Driver |---| File |
+-----------+ +-----+ +-------+--------+ +----+----+
| Browser | | GUI | | |
+-----+-----+ +--+--+ | |
| | | |
| +---+-------------+--+ |
N D S | | IPP Client |--------------+
O I E | +---------+----------+
T R C | |
I E U |
F C R -------------- Transport -------------------
I T I
C O T | --+
A R Y +--------+--------+ |
T Y | IPP Server | |
I +--------+--------+ |
O | |
N +-----------------+ | IPP Printer
| Print Service | |
+-----------------+ |
| --+
+-----------------+
| Output Device(s)|
+-----------------+
Figure 1: IPP Model
An IPP Printer object ("Printer") encapsulates the functions normally
associated with physical Output Devices along with the spooling,
scheduling, and multiple device management functions often associated
with a print server. Printers are optionally registered as entries
in a directory where End Users find and select them based on some
sort of filtered context-based searching mechanism (see Appendix D).
The directory is used to store relatively static information about
the Printer, allowing End Users to search for and find Printers that
match their search criteria -- for example, name, location, context,
Printer capabilities, etc. The more dynamic information, such as
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state, currently loaded and ready media, number of Jobs at the
Printer, errors, warnings, and so forth, is directly associated with
the Printer itself rather than with the entry in the directory, which
only references the Printer.
IPP Clients ("Clients") implement IPP on the Client side and give
End Users (or programs running on behalf of End Users) the ability to
query Printers and submit and manage Print Jobs. An IPP server is
just that part of the Printer object that implements the server-side
protocol. The rest of the Printer object implements (or gateways
into) the application semantics of the print service itself.
Printers can be embedded in an Output Device or can be implemented on
a host on the network that communicates with an Output Device.
When a Job is submitted to the Printer and the Printer has validated
the attributes in the submission request, the Printer creates a new
IPP Job object ("Job"). The End User then interacts with this new
Job to query its status and monitor the progress of the Job. An
End User can also cancel their Print Jobs by using the Job's
Cancel-Job operation. An End User can also hold, release, and
restart their Print Jobs using the Job's OPTIONAL Hold-Job,
Release-Job, and Restart-Job operations, if implemented.
A privileged Operator or Administrator of a Printer can cancel, hold,
release, and restart any user's Job using the REQUIRED Cancel-Job and
the OPTIONAL Hold-Job, Release-Job, and Restart-Job operations. In
addition, a privileged Operator or Administrator of a Printer can
pause, resume, or purge (Jobs from) a Printer using the OPTIONAL
Pause-Printer, Resume-Printer, and Purge-Jobs operations, if
implemented.
The notification service is defined in "Internet Printing Protocol
(IPP): Event Notifications and Subscriptions" [RFC3995]. By using
such a notification service, the End User is able to register for and
receive Printer-specific and Job-specific events asynchronously.
Otherwise, an End User can query the status of Printers and can
follow the progress of Jobs by polling using the
Get-Printer-Attributes, Get-Jobs, and Get-Job-Attributes operations.
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2. Conventions Used in This Document
2.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
The key word "DEPRECATED" in this document refers to an operation,
attribute, or value that SHOULD NOT be used or supported in new
implementations.
2.2. Printing Terminology
Client: Initiator of outgoing IPP session requests and sender of
outgoing IPP operation requests (Hypertext Transfer Protocol
(HTTP/1.1) user agent, as defined in [RFC7230]).
Document: An object created and managed by a Printer that contains
description, processing, and status information. A Document object
can have attached data and is bound to a single Job [PWG5100.5].
'ipp' URI: An IPP URI as defined in [RFC3510].
'ipps' URI: An IPP URI as defined in [RFC7472].
Job: An object created and managed by a Printer that contains
description, processing, and status information. The Job also
contains zero or more Document objects.
Logical Device: A print server, software service, or gateway that
processes Jobs and either forwards or stores the processed Job or
uses one or more Physical Devices to render output.
Output Device: A single Logical or Physical Device.
Physical Device: A hardware implementation of an endpoint device,
e.g., a marking engine, a fax modem, etc.
Printer: Listener for incoming IPP session requests and receiver of
incoming IPP operation requests (HTTP/1.1 server, as defined in
[RFC7230]) that represents one or more Physical Devices or a Logical
Device.
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2.3. Model Terminology
2.3.1. Administrator
An End User who is also authorized to manage all aspects of an Output
Device or Printer, including creating the Printer instances and
controlling the authorization of other End Users and Operators
[RFC2567].
2.3.2. Attributes
An attribute is an item of information that is associated with an
instance of an IPP object (Printer, Job, etc.). An attribute
consists of an attribute name and one or more attribute values. Each
attribute has a specific attribute syntax. All object attributes are
defined in Section 5, and all operation attributes are defined in
Section 4.
Job Template attributes are described in Section 5.2. The Client
optionally supplies Job Template attributes in a Job Creation request
(operation requests that create Job objects). The Printer object has
associated attributes that define supported and default values for
the Printer.
2.3.2.1. Attribute Group Name
Related attributes are grouped into named groups. The name of the
group is a keyword. The group name can be used in place of naming
all the attributes in the group explicitly. Attribute groups are
defined in Section 4.
2.3.2.2. Attribute Name
Each attribute is uniquely identified in this document by its
attribute name. An attribute name is a keyword. The keyword
attribute name is given in the section title in this document that
describes that attribute. In running text in this document,
attribute names are indicated inside double quotation marks (") where
the quotation marks are not part of the keyword itself.
2.3.2.3. Attribute Syntax
Each attribute is defined using an explicit syntax type. In this
document, each syntax type is defined as a keyword with specific
meaning. The "Encoding and Transport" document [RFC8010] indicates
the actual "on-the-wire" encoding rules for each syntax type.
Attribute syntax types are defined in Section 5.1.
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2.3.2.4. Attribute Value
Each attribute has one or more values. Attribute values are
represented in the syntax type specified for that attribute. In
running text in this document, attribute values are indicated inside
single quotation marks ('), whether their attribute syntax is
keyword, integer, text, etc. where the quotation marks are not part
of the value itself.
2.3.3. End User
An End User is a person or software process that is authorized to
perform basic printing functions, including finding/locating a
Printer, creating a local instance of a Printer, viewing Printer
status, viewing Printer capabilities, submitting a Print Job, viewing
Print Job status, and altering the attributes of a Print Job
[RFC2567].
2.3.4. Impression
An Impression is the content imposed upon one side of a Media Sheet
by a marking engine, independent of the number of times that the
sheet side passes any marker. An Impression contains one or more
Input Pages that are imposed (scaled, translated, and/or rotated)
during processing of the Document data.
2.3.5. Input Page
An Input Page is a page according to the definition of "pages" in the
language used to express the Document data.
2.3.6. Job Creation Operation
A Job Creation operation is any operation that causes the creation of
a Job object, e.g., the Create-Job, Print-Job, and Print-URI
operations defined in this document.
2.3.7. Keyword
Keywords are used within this document as identifiers of semantic
entities within the abstract model (see Section 5.1.4). Attribute
names, some attribute values, attribute syntaxes, and attribute group
names are represented as keywords.
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2.3.8. Media Sheet
A Media Sheet is a single instance of a medium, whether printing on
one or both sides of the medium. Media Sheets also include sections
of roll media.
2.3.9. Operator
An Operator is an End User that also has special rights on the Output
Device or Printer. The Operator typically monitors the status of the
Printer and also manages and controls the Jobs at the Output Device
[RFC2567]. The Operator is allowed to query and control the Printer,
Jobs, and Documents based on site policy.
2.3.10. Set
A Set is a logical boundary between the delivered Media Sheets of a
printed Job. For example, in the case of a ten-page single Document
with collated pages and a request for 50 copies, each of the 50
printed copies of the Document constitutes a Set. If the pages were
uncollated, then 50 copies of each of the individual pages within the
Document would represent each Set. Finishing processes operate on
Sets.
2.3.11. Support of Attributes
By definition, a Printer supports an attribute only if that Printer
accepts it in a request or responds with the corresponding attribute
populated with some value(s) in a response to a query for that
attribute. A Printer supports an attribute value if the value is one
of the Printer's "supported values" attributes. The device behind a
Printer can exhibit a behavior that corresponds to some IPP
attribute, but if the Printer, when queried for that attribute,
doesn't respond with the attribute, then as far as IPP is concerned,
that implementation does not support that feature. If the Printer's
"xxx-supported" attribute is not populated with a particular value
(even if that value is a legal value for that attribute), then that
Printer does not support that particular value.
A conforming implementation supports all REQUIRED attributes.
However, even for REQUIRED attributes, conformance to IPP does not
mandate that all implementations support all possible values
representing all possible Job processing behaviors and features. For
example, if a given instance of a Printer supports only certain
Document formats, then that Printer responds with the
"document-format-supported" attribute populated with a set of values,
or possibly only one value, taken from the entire set of possible
values defined for that attribute. This limited set of values
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represents the Printer's set of supported Document formats.
Supporting an attribute and some set of values for that attribute
enables IPP End Users to be aware of and make use of those features
associated with that attribute and those values. If an
implementation chooses to not support an attribute or some specific
value, then IPP End Users would have no ability to make use of that
feature within the context of IPP itself. However, due to existing
practice and legacy systems that are not IPP aware, there might be
some other mechanism outside the scope of IPP to control or request
the "unsupported" feature (such as embedded instructions within the
Document data itself).
For example, consider the following for the "finishings-supported"
attribute.
1) If a Printer is not physically capable of stapling, the
"finishings-supported" attribute MUST NOT be populated with the
value of 'staple'.
2) A Printer is physically capable of stapling; however, an
implementation chooses not to support stapling in the IPP
"finishings" attribute. In this case, 'staple' MUST NOT be a
value in the "finishings-supported" Printer Description
attribute. Without support for the value 'staple', an IPP
End User would have no means within the protocol itself to
request that a Job be stapled. However, an existing Document
data formatter might be able to request that the Document be
stapled directly with an embedded instruction within the Document
data. In this case, the IPP implementation does not "support"
stapling; however, the End User is still able to have some
control over the stapling of the completed Job.
3) A Printer is physically capable of stapling, and an
implementation chooses to support stapling in the IPP
"finishings" attribute. In this case, 'staple' MUST be a value
in the "finishings-supported" Printer attribute. Doing so
enables End Users to be aware of and make use of the stapling
feature using IPP attributes.
Even though support for Job Template attributes by a Printer is
OPTIONAL in IPP/1.1, Printers whose associated device(s) is capable
of realizing any feature or function that corresponds to an IPP
attribute and some associated value SHOULD support that IPP attribute
and value.
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The set of values in any of the supported value attributes is set
(populated) by some administrative process or automatic sensing
mechanism that is outside the scope of this document. For
administrative policy and control reasons, an Administrator can
choose to make only a subset of possible values visible to the
End User. In this case, the real Output Device behind the IPP
Printer abstraction can be capable of a certain feature; however, an
Administrator is specifying that access to that feature not be
exposed to the End User through IPP. Also, since a Printer can
represent a logical print device (not just a Physical Device), the
actual process for supporting a value is undefined and left up to the
implementation. However, if a Printer supports a value, some manual
human action might be needed to realize the semantic action
associated with the value, but no End User action is required.
For example, if one of the values in the "finishings-supported"
attribute is 'staple', the actual process might be an automatic
staple action by a Physical Device controlled by some command sent to
the device. Or, the actual process of stapling might be a manual
action by an Operator at an Operator-attended Printer.
For another example of how supported attributes function, consider an
Administrator who desires to control all Print Jobs so that no Job
sheets are printed in order to conserve paper. To force no Job
sheets, the Administrator sets the only supported value for the
"job-sheets-supported" attribute to 'none'. In this case, if a
Client requests anything except 'none', the Job Creation request is
rejected or the "job-sheets" value is ignored (depending on the value
of "ipp-attribute-fidelity"). To force the use of Job start/end
sheets on all Jobs, the Administrator does not include the value
'none' in the "job-sheets-supported" attribute. In this case, if a
Client requests 'none', the Job Creation request is rejected or the
"job-sheets" value is ignored (again depending on the value of
"ipp-attribute-fidelity").
Job Template attributes will typically have corresponding
"xxx-supported" and "xxx-default" Printer Description attributes that
contain the supported and default values for the attribute. For
capabilities that are not associated with a Job, the convention is to
have an "xxx-supported" Printer Description attribute that lists the
supported values and an "xxx-configured" Printer Description
attribute that contains the value being used by the Printer. For
example, the "charset-supported" Printer Description attribute
(Section 5.4.18) lists the supported character sets for the Printer
while the "charset-configured" Printer Description attribute
(Section 5.4.17) specifies the character set being used by the
Printer.
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2.3.12. Terminating State
The final state for a Job or other object is called its Terminating
State. For example, the 'aborted', 'canceled', and 'completed' Job
states are Terminating States.
2.4. Abbreviations
ABNF: Augmented Backus-Naur Form [RFC5234]
ASCII: American Standard Code for Information Interchange [RFC20]
HTTP: Hypertext Transfer Protocol [RFC7230]
HTTPS: HTTP over TLS [RFC2818]
IANA: Internet Assigned Numbers Authority
IEEE: Institute of Electrical and Electronics Engineers
IESG: Internet Engineering Steering Group
IPP: Internet Printing Protocol (this document, [RFC8010], and
[PWG5100.12])
ISTO: IEEE Industry Standards and Technology Organization
LPD: Line Printer Daemon Protocol [RFC1179]
PWG: IEEE-ISTO Printer Working Group
RFC: Request for Comments
TCP: Transmission Control Protocol [RFC793]
TLS: Transport Layer Security [RFC5246]
URI: Uniform Resource Identifier [RFC3986]
URL: Uniform Resource Locator [RFC3986]
UTF-8: Unicode Transformation Format - 8-bit [RFC3629]
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3. IPP Objects
This document defines IPP objects of types Printer and Job. Each
type of object models relevant aspects of a real-world entity such as
a real Printer or real Print Job. Each object type is defined as a
set of possible attributes that can be supported by instances of that
object type. For each object (instance), the actual set of supported
attributes and values describe a specific implementation. The
object's attributes and values describe its state, capabilities,
realizable features, Job processing functions, and default behaviors
and characteristics. For example, the Printer object type is defined
as a set of attributes that each Printer object potentially supports.
In the same manner, the Job object type is defined as a set of
attributes that are potentially supported by each Job object.
Each attribute included in the set of attributes defining an object
type is labeled as:
o "REQUIRED": each object MUST support the attribute.
o "RECOMMENDED": each object SHOULD support the attribute.
o "OPTIONAL": each object MAY support the attribute.
Some definitions of attribute values indicate that an object MUST or
SHOULD support the value; otherwise, support of the value is
OPTIONAL. However, if an implementation supports an attribute, it
MUST support at least one of the possible values for that attribute.
3.1. Printer Object
The major component of the IPP Model is the Printer object. A
Printer object implements the server side of the IPP/1.1 protocol.
Using the protocol, End Users can query the attributes of the Printer
object and submit Print Jobs to the Printer object. The actual
implementation components behind the Printer abstraction can take on
different forms and different configurations. However, the model
abstraction allows the details of the configuration of real
components to remain opaque to the End User. Section 4 describes
each of the Printer operations in detail.
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The capabilities and state of a Printer object are described by its
attributes. Printer attributes are divided into two groups:
o "job-template" attributes: These attributes describe supported Job
processing capabilities and defaults for the Printer object (see
Section 5.2)
o "printer-description" attributes: These attributes describe the
Printer's identification, state, location, references to other
sources of information about the Printer object, etc. (see
Section 5.4)
Since a Printer object is an abstraction of a generic Document Output
Device and print service provider, a Printer object could be used to
represent any real or virtual device with semantics consistent with
the Printer object, such as a fax device, an imager, or even a CD
writer.
Some examples of configurations supporting a Printer object include:
1. An Output Device with no spooling capabilities
2. An Output Device with a built-in spooler
3. A print server supporting IPP with one or more associated Output
Devices
3a. The associated Output Devices are or are not capable of
spooling Jobs
3b. The associated Output Devices possibly support IPP
Figure 2 shows some examples of how Printers can be realized on top
of various distributed printing configurations. The embedded case
below represents configurations 1 and 2 above. The "hosted Printer"
and "fan out" items represent configurations 3a and 3b, respectively.
In this document, the term "Client" refers to a software entity that
sends IPP operation requests to an IPP Printer and accepts IPP
operation responses. A Client MAY be:
1. contained within software controlled by an End User, e.g.,
activated by the "Print" menu item in an application, or
2. the print server component that sends IPP requests to either an
Output Device or another "downstream" print server.
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The term "IPP Printer" is a network entity that accepts IPP operation
requests and returns IPP operation responses. As such, an IPP
Printer object MAY be:
1. an (embedded) device component that accepts IPP requests and
controls the device, or
2. a component of a print server that accepts IPP requests (where
the print server controls one or more networked devices using IPP
or other protocols).
Legend:
##### indicates a Printer object that is
either embedded in an Output Device or
hosted in a server. The Printer object
might or might not be capable of queuing/spooling.
any indicates any network protocol or direct
connect, including IPP
embedded Printer:
Output Device
+---------------+
O +--------+ | ########### |
/|\ | Client |------------IPP------------># Printer # |
/ \ +--------+ | # Object # |
| ########### |
+---------------+
hosted Printer:
+---------------+
O +--------+ ########### | |
/|\ | Client |--IPP--># Printer #-any->| Output Device |
/ \ +--------+ # Object # | |
########### +---------------+
+---------------+
fan out: | |
+-->| Output Device |
any/ | |
O +--------+ ########### / +---------------+
/|\ | Client |-IPP-># Printer #--*
/ \ +--------+ # Object # \ +---------------+
########### any\ | |
+-->| Output Device |
| |
+---------------+
Figure 2: IPP Printer Object Architecture
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3.2. Job Object
A Job object is used to model a Print Job. A Job object contains
zero or more Documents. The information required to create a Job
object is sent in a Job Creation request from the End User via an IPP
Client to the Printer. The Printer validates the Job Creation
request, and if the Printer accepts the request, the Printer creates
the new Job object. Section 4 describes each of the Job operations
in detail.
The characteristics and state of a Job object are described by its
attributes. Job attributes are grouped into two groups as follows:
o "job-template" attributes: These attributes can be supplied by the
Client or End User and include Job processing instructions that
are intended to override any Printer defaults and/or instructions
embedded within the Document data (see Section 5.2)
o "job-description" attributes: These attributes describe the Job's
identification, state, size, etc. The Client supplies some of
these attributes, and the Printer generates others (see
Section 5.3)
An implementation MUST support at least one Document per Job object.
An implementation MAY support multiple Documents per Job object. A
Document is either:
o a stream of Document data in a format supported by the Printer
(typically a Page Description Language -- PDL), or
o a reference to such a stream of Document data.
All Job processing instructions are modeled as Job object attributes.
These attributes are called "Job Template attributes", and they apply
equally to all Documents within a Job object.
3.3. Object Relationships
IPP objects have relationships that are maintained persistently along
with the persistent storage of the object attributes.
A Printer object can represent either one or more physical Output
Devices or a Logical Device that "processes" Jobs but never actually
uses a physical Output Device to put marks on paper. Examples of
Logical Devices include a web page publisher or a gateway into an
online Document archive or repository. A Printer contains zero or
more Job objects.
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A Job object is contained by exactly one Printer; however, the
identical Document data associated with a Job could be sent to either
the same or a different Printer. In this case, a second Job object
would be created that would be almost identical to the first Job;
however, it would have new (different) Job object identifiers (see
Section 3.4).
A Job either is empty (before any Documents have been added) or
contains one or more Documents. If the contained Document is a
stream of Document data, that stream can be contained in only one
Document. However, there can be identical copies of the stream in
other Documents in the same or different Jobs. If the contained
Document is just a reference to a stream of Document data, other
Documents (in the same or different Job(s)) contain the same
reference.
3.4. Object Identity
All IPP objects (Printers, Jobs, etc.) are identified by a Uniform
Resource Identifier (URI) [RFC3986] so that they can be persistently
and unambiguously referenced. Since every URL is a specialized form
of a URI, even though the more generic term "URI" is used throughout
the rest of this document, its usage is intended to cover the more
specific notion of "URL" as well.
An Administrator configures Printers to either support or not support
authentication and/or message privacy using Transport Layer Security
(TLS) [RFC5246]; the mechanism for security configuration is outside
the scope of this document. In some situations, both types of
connections (both authenticated and unauthenticated) can be
established using a single communication channel that has some sort
of negotiation mechanism. In other situations, multiple
communication channels are used, one for each type of security
configuration. Section 9 provides a full description of all security
considerations and configurations.
If a Printer supports more than one communication channel, some or
all of those channels might support and/or require different security
mechanisms. In such cases, an Administrator could expose the
simultaneous support for these multiple communication channels as
multiple URIs for a single Printer where each URI represents one of
the communication channels to the Printer. To support this
flexibility, the IPP Printer object type defines a multi-valued
identification attribute called the "printer-uri-supported" attribute
that MUST contain at least one URI. The "printer-uri-supported"
attribute has two companion attributes, the "uri-security-supported"
attribute and the "uri-authentication-supported" attribute. Both
have the same cardinality as "printer-uri-supported". The purpose of
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the "uri-security-supported" attribute is to indicate the security
mechanisms (if any) used for each URI listed in
"printer-uri-supported". The purpose of the
"uri-authentication-supported" attribute is to indicate the
authentication mechanisms (if any) used for each URI listed in
"printer-uri-supported". These three attributes are fully described
in Sections 5.4.1, 5.4.2, and 5.4.3.
When a Job is submitted to the Printer via a Job Creation request,
the Client supplies only a single Printer URI. The Client-supplied
Printer URI MUST be one of the values in the "printer-uri-supported"
Printer attribute.
IPP/1.1 does not specify how the Client obtains the Client-supplied
URI, but it is RECOMMENDED that a Printer be registered as an entry
in a directory service. End Users and programs can then interrogate
the directory, searching for Printers. Appendix D defines a generic
schema for Printer object entries in the directory service and
describes how the entry acts as a bridge to the actual IPP Printer.
The entry in the directory that represents the IPP Printer includes
the possibly many URIs for that Printer as values in one of its
attributes.
When a Client submits a Job Creation request to the Printer, the
Printer validates the request and creates a new Job object. The
Printer assigns the new Job a numeric identifier that is stored in
the "job-id" Job attribute and a URI that is stored in the "job-uri"
Job attribute. Both the numeric identifier and URI can then be used
by Clients as the target for subsequent Job operations; the numeric
identifier is preferred. The Printer generates the Job numeric
identifier and URI based on its configured security policy and the
URI used by the Client in the Job Creation request.
For example, consider a Printer that supports both a communication
channel secured by the use of TLS (using HTTP over TLS with an
"https" schemed URI) and another open communication channel that is
not secured with TLS (using a simple "http" schemed URI). If a
Client submits a Job using the secure URI, the Printer assigns the
new Job a secure URI as well. If a Client were to submit a Job using
the open-channel URI, the Printer might assign the new Job an
open-channel URI. Clients SHOULD use the "printer-uri" and "job-id"
attributes to target a Job to avoid any ambiguity about the security
of the communication channel.
In addition, the Printer also populates the Job's "job-printer-uri"
attribute. This is a reference back to the Printer that created the
Job. If a Client only has access to a Job's "job-uri" identifier,
the Client can query the Job's "job-printer-uri" attribute in order
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to determine which Printer created the Job. If the Printer supports
more than one URI, the Printer picks the one URI supplied by the
Client when creating the Job to build the value for and to populate
the Job's "job-printer-uri" attribute.
In addition to identifiers, IPP objects have names -- "printer-name"
for Printers and "job-name" for Jobs. An object name is not
guaranteed to be unique across all instances of all objects. A
Printer's name is chosen and set by an Administrator through some
mechanism outside the scope of this document. A Job's name can be
chosen and supplied by the Client submitting the Job. If the Client
does not supply a Job name, the Printer generates a name for the new
Job. In all cases, the name only has local meaning.
To summarize:
o Each Printer is identified by one or more URIs. The Printer's
"printer-uri-supported" attribute contains the URI(s).
o The Printer's "uri-security-supported" attribute identifies the
communication channel security protocols that have been configured
for the various Printer URIs (e.g., 'tls' or 'none').
o The Printer's "uri-authentication-supported" attribute identifies
the authentication mechanisms that have been configured for the
various Printer URIs (e.g., 'digest', 'none', etc.).
o Each Job is identified by a numeric identifier, which is a 32-bit
positive integer. The Job's "job-id" attribute contains the
Job ID. The Job ID is only unique within the context of the
Printer that created the Job.
o Each Job is also identified by a URI. The Job's "job-uri"
attribute contains the URI, although its use by Clients is
DEPRECATED.
o Each Job has a "job-printer-uri" attribute, which contains the URI
of the Printer that was used to create the Job. This attribute is
used to determine the Printer that created a Job when given only
the URI for the Job. This linkage is necessary to determine the
languages, charsets, and operations that are supported on that Job
(the basis for such support comes from the creating Printer).
o Each Printer has a name, which is not necessarily unique. The
Administrator chooses and sets this name through some mechanism
outside the scope of this IPP/1.1 document. The Printer's
"printer-name" attribute contains the name.
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o Each Job has a name, which is not necessarily unique. The Client
optionally supplies this name in the Job Creation request. If the
Client does not supply this name, the Printer generates a name for
the Job. The Job's "job-name" attribute contains the name.
4. IPP Operations
IPP objects (Printers, Jobs, etc.) support operations. An operation
consists of a request and a response. When a Client communicates
with a Printer or its Jobs, the Client issues an operation request to
the Printer URI and object's numeric identifier, if needed.
Operation requests and responses have parameters that identify the
operation. Operations also have attributes that affect the runtime
characteristics of the operation (the intended target, localization
information, etc.). These operation-specific attributes are called
"operation attributes" (as compared to object attributes such as
Printer attributes or Job attributes). Each request carries along
with it any operation attributes, object attributes, and/or Document
data required to perform the operation. Each request requires a
response from the object. Each response indicates success or failure
of the operation with a status-code as a response parameter. The
response contains any operation attributes, object attributes, and/or
status messages generated during the execution of the operation
request.
This section describes the semantics of the IPP operations, both
requests and responses, in terms of the parameters, attributes, and
other data associated with each operation.
The Printer operations defined in this document are:
Print-Job (Section 4.2.1)
Print-URI (Section 4.2.2)
Validate-Job (Section 4.2.3)
Create-Job (Section 4.2.4)
Get-Printer-Attributes (Section 4.2.5)
Get-Jobs (Section 4.2.6)
Pause-Printer (Section 4.2.7)
Resume-Printer (Section 4.2.8)
Purge-Jobs (Section 4.2.9)
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The Job operations defined in this document are:
Send-Document (Section 4.3.1)
Send-URI (Section 4.3.2)
Cancel-Job (Section 4.3.3)
Get-Job-Attributes (Section 4.3.4)
Hold-Job (Section 4.3.5)
Release-Job (Section 4.3.6)
Restart-Job (Section 4.3.7)
The Send-Document and Send-URI Job operations are used to add
Documents to an existing Job created using the Create-Job operation.
4.1. Common Semantics
All IPP operations require some common parameters and operation
attributes. These common elements and their semantic characteristics
are defined and described in more detail in the following sections.
4.1.1. Required Parameters
Every operation request contains the following REQUIRED parameters:
o a "version-number",
o an "operation-id",
o a "request-id", and
o the attributes that are REQUIRED for that type of request.
Every operation response contains the following REQUIRED parameters:
o a "version-number",
o a "status-code",
o the "request-id" that was supplied in the corresponding request,
and
o the attributes that are REQUIRED for that type of response.
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The Encoding and Transport document [RFC8010] defines special rules
for the encoding of these parameters. All other operation elements
are represented using the more generic encoding rules for attributes
and groups of attributes.
4.1.2. Operation IDs and Request IDs
Each IPP operation request includes an identifying "operation-id"
value. Valid values are defined in the "operations-supported"
Printer attribute section (see Section 5.4.15). The Client specifies
which operation is being requested by supplying the correct
"operation-id" value.
In addition, every invocation of an operation is identified by a
"request-id" value. For each request, the Client chooses the
"request-id", which MUST be an integer (possibly unique, depending on
Client requirements) in the range from 1 to 2**31 - 1 (inclusive).
This "request-id" allows Clients to manage multiple outstanding
requests. The receiving IPP object (Printer, Job, etc.) copies all
32 bits of the Client-supplied "request-id" attribute into the
response so that the Client can match the response with the correct
outstanding request, even if the "request-id" is out of range. If
the request is terminated before the complete "request-id" is
received, the IPP object rejects the request and returns a response
with a "request-id" of 0.
Note: In some cases, the transport protocol underneath IPP might be a
connection-oriented protocol that would make it impossible for a
Client to receive responses in any order other than the order in
which the corresponding requests were sent. In such cases, the
"request-id" attribute would not be essential for correct protocol
operation. However, in other transport mappings the operation
responses could come back in any order, in which case the
"request-id" is essential.
4.1.3. Attributes
Operation requests and responses are both composed of groups of
attributes and/or Document data. The attribute groups are:
o Operation Attributes: These attributes are passed in the operation
and affect the IPP object's behavior while processing the
operation request, and they can affect other attributes or groups
of attributes. Some operation attributes describe the Document
data associated with the Print Job and are associated with new Job
objects; however, most operation attributes do not persist beyond
the life of the operation. The description of each operation
attribute includes conformance statements indicating which
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operation attributes are REQUIRED and which are OPTIONAL for an
IPP object to support, as well as which attributes a Client MUST
supply in a request and an IPP object MUST supply in a response.
o Job Template Attributes: These attributes affect the processing of
a Job. A Client MAY supply Job Template attributes in a Job
Creation request, and the receiving object MUST be prepared to
receive all supported attributes. The Job object can later be
queried to find out what Job Template attributes were originally
requested in the Job Creation request, and such attributes are
returned in the response as Job object attributes. The Printer
object can be queried about its Job Template attributes to find
out what type of Job processing capabilities are supported and/or
what the default Job processing behaviors are, though such
attributes are returned in the response as Printer object
attributes. The "ipp-attribute-fidelity" operation attribute
affects processing of all Client-supplied Job Template attributes
-- see Section 4.2.1.1 and Appendix C for a full description of
"ipp-attribute-fidelity" and its relationship to other attributes.
o Job Object Attributes: These attributes are returned in response
to a query operation directed at a Job object.
o Printer Object Attributes: These attributes are returned in
response to a query operation directed at a Printer object.
o Unsupported Attributes: In a Job Creation request, the Client
supplies a set of operation and Job Template attributes. If any
of these attributes or their values are unsupported by the Printer
object, the Printer object SHOULD return the set of unsupported
attributes in the response. Section 4.1.7, Section 4.2.1.2, and
Appendix C give a full description of how Job Template attributes
supplied by the Client in a Job Creation request are processed by
the Printer object and how unsupported attributes are returned to
the Client. Because of extensibility, any IPP object might
receive a request that contains new or unknown attributes or
values for which it has no support. In such cases, the IPP object
processes what it can and returns the unsupported attributes in
the response. The Unsupported Attributes group is defined for all
operation responses for returning unsupported attributes that the
Client supplied in the request.
Later in this section, each operation is formally defined by
identifying the allowed and expected groups of attributes for each
request and response. The model identifies a specific order for each
group in each request or response, but the attributes within each
group can be in any order, unless specified otherwise.
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The attributes within a group MUST be unique; if an attribute with
the same name occurs more than once, the group is malformed. Clients
MUST NOT submit such malformed requests, and Printers MUST NOT return
such malformed responses. If such a malformed request is submitted
to a Printer, the Printer MUST either (1) reject the request with the
'client-error-bad-request' status-code (RECOMMENDED -- see
Appendix B.1.4.1) or (2) process the request normally after selecting
only one of the attribute instances, depending on implementation.
Which attribute is selected when there are duplicate attributes
depends on implementation. The IPP Printer MUST NOT use the values
from more than one such duplicate attribute instance.
Each attribute definition includes the attribute's name followed by
the name of its attribute syntax(es) in parentheses. In addition,
each 'integer' attribute can be followed by the allowed range in
parentheses, (m:n), for values of that attribute. Each 'text' or
'name' attribute can be followed by the maximum size in octets in
parentheses, (size), for values of that attribute. For more details
on attribute syntax notation, see the descriptions of these attribute
syntaxes in Section 5.1.
Note: Document data included in the operation is not strictly an
attribute, but it is treated as a special attribute group for
ordering purposes. The only operations defined in this document that
support supplying the Document data within an operation request are
Print-Job and Send-Document. There are no operations defined in this
document whose responses include Document data.
Some operations are REQUIRED for IPP objects to support; the others
are OPTIONAL (see Section 6.2.2). Therefore, before using an
OPTIONAL operation, a Client SHOULD first use the REQUIRED
Get-Printer-Attributes operation to query the Printer's
"operations-supported" attribute in order to determine which OPTIONAL
operations are actually supported. The Client SHOULD NOT use an
OPTIONAL operation that is not supported. When an IPP object
receives a request to perform an operation it does not support, it
MUST return the 'server-error-operation-not-supported' status-code
(see Appendix B.1.5.2). An IPP object is non-conformant if it does
not support a REQUIRED operation.
4.1.4. Character Set and Natural Language Operation Attributes
Some Job and Printer attributes have values that are text strings and
names intended for human understanding rather than machine
understanding (see the 'text' and 'name' attribute syntax
descriptions in Section 5.1). The following sections describe two
special operation attributes called "attributes-charset" and
"attributes-natural-language" whose values are used when interpreting
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other attributes using the 'text' and 'name' attribute syntaxes. For
Job Creation operations, the IPP Printer implementation also saves
these two attributes with the new Job object as Job Status
attributes.
The "attributes-charset" and "attributes-natural-language" attributes
MUST be the first two attributes in every IPP request and response,
as part of the initial Operation Attributes group of the IPP message.
The "attributes-charset" attribute MUST be the first attribute in the
group, and the "attributes-natural-language" attribute MUST be the
second attribute in the group.
For the sake of brevity in this document, these operation attribute
descriptions are not repeated with every operation request and
response but instead have a reference back to this section.
4.1.4.1. Request Operation Attributes
The Client MUST supply and the Printer object MUST support the
following REQUIRED operation attributes in every IPP operation
request:
"attributes-charset" (charset):
This operation attribute identifies the charset (coded character
set and encoding method) used by any 'text' and 'name' attributes
that the Client is supplying in this request. It also identifies
the charset that the Printer object MUST use (if supported) for
all 'text' and 'name' attributes and status messages that the
Printer object returns in the response to this request. See
Sections 5.1.2 and 5.1.3 for the definitions of the 'text' and
'name' attribute syntaxes.
All Clients and IPP objects MUST support the 'utf-8' charset
[RFC3629] and MAY support additional charsets, provided that they
are registered with IANA [RFC2978] [IANA-CS]. If the Printer
object does not support the Client-supplied charset value, the
Printer object MUST reject the request, set the
"attributes-charset" to 'utf-8' in the response, and return the
'client-error-charset-not-supported' status-code and any 'text' or
'name' attributes using the 'utf-8' charset. The Printer MAY
return any attributes in the Unsupported Attributes group (see
Sections 4.1.7 and 4.2.1.2). The Printer object MUST indicate the
charset(s) supported as the values of the "charset-supported"
Printer attribute (see Section 5.4.18), so that the Client can
query to determine which charset(s) is supported.
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Note to Client implementors: Since IPP objects are only required
to support the 'utf-8' charset, in order to maximize
interoperability with multiple IPP object implementations, a
Client SHOULD supply 'utf-8' in the "attributes-charset" operation
attribute, even though the Client is only passing and able to
present a simpler charset, such as US-ASCII [RFC20] or ISO-8859-1
[ISO8859-1]. Then the Client will have to filter out, perform
charset conversion on, or replace those characters that are
returned in the response that it cannot present to its user. On
the other hand, if both the Client and the IPP objects also
support a charset in common besides 'utf-8', the Client can use
that charset in order to avoid charset conversion or data loss.
See the 'charset' attribute syntax description in Section 5.1.8
for the syntax and semantic interpretation of the values of this
attribute and for example values.
"attributes-natural-language" (naturalLanguage):
This operation attribute identifies the natural language [RFC5646]
used by any 'text' and 'name' attributes that the Client is
supplying in this request. This attribute also identifies the
natural language that the Printer object SHOULD use for all 'text'
and 'name' attributes and status messages that the Printer object
returns in the response to this request. See the
'naturalLanguage' attribute syntax description in Section 5.1.9
for the syntax and semantic interpretation of the values of this
attribute and for example values.
There are no REQUIRED natural languages required for the Printer
object to support. However, the Printer's
"generated-natural-language-supported" attribute identifies the
natural languages supported by the Printer object and any
contained Jobs for all text strings generated by the IPP object.
A Client MAY query this attribute to determine which natural
language(s) is supported for generated messages.
For any of the attributes for which the Printer object generates
text, i.e., for the "job-state-message", "printer-state-message",
and status messages (see Section 4.1.6), the Printer object MUST
be able to generate these text strings in any of its supported
natural languages. If the Client requests a natural language that
is not supported, the Printer object MUST return these generated
messages in the Printer's configured natural language as specified
by the Printer's "natural-language-configured" attribute (see
Section 5.4.19).
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For other 'text' and 'name' attributes supplied by the Client,
authentication system, Operator, Administrator, or manufacturer
(i.e., for "job-originating-user-name", "printer-name" (name),
"printer-location" (text), "printer-info" (text), and
"printer-make-and-model" (text)), the Printer object is only
required to support the configured natural language of the Printer
identified by the Printer's "natural-language-configured"
attribute, though support of additional natural languages for
these attributes is permitted.
For any 'text' or 'name' attribute in the request that is in a
different natural language than the value supplied in the
"attributes-natural-language" operation attribute, the Client MUST
use the Natural Language Override mechanism (see Sections 5.1.2.2
and 5.1.3.2) for each such attribute value supplied. The Client
MAY use the Natural Language Override mechanism redundantly, i.e.,
use it even when the value is in the same natural language as the
value supplied in the "attributes-natural-language" operation
attribute of the request.
The IPP object MUST accept any natural language and any Natural
Language Override, whether the IPP object supports that natural
language or not (and independent of the value of the
"ipp-attribute-fidelity" operation attribute). That is, the IPP
object accepts all Client-supplied values no matter what the
values are in the Printer's "generated-natural-language-supported"
attribute. That attribute,
"generated-natural-language-supported", only applies to generated
messages, not Client-supplied messages. The IPP object MUST
remember that natural language for all Client-supplied attributes,
and when returning those attributes in response to a query, the
IPP object MUST indicate that natural language.
Each value whose attribute syntax type is 'text' or 'name' (see
Sections 5.1.2 and 5.1.3) has an Associated Natural Language.
This document does not specify how this association is stored in a
Printer or Job object. When such a value is encoded in a request
or response, the natural language is either implicit or explicit:
* In the implicit case, the value contains only the text/name
value, and the language is specified by the
"attributes-natural-language" operation attribute in the
request or response (see Sections 5.1.2.1 and 5.1.3.1).
* In the explicit case (also known as the Natural Language
Override case), the value contains both the language and the
text/name value (see Sections 5.1.2.2 and 5.1.3.2).
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For example, the "job-name" attribute MAY be supplied by the
Client in a Job Creation request. The text value for this
attribute will be in the natural language identified by the
"attribute-natural-language" attribute, or if different, as
identified by the Natural Language Override mechanism. If
supplied, the IPP object will use the value of the "job-name"
attribute to populate the Job's "job-name" attribute. Whenever
any Client queries the Job's "job-name" attribute, the IPP object
returns the attribute as stored and uses the Natural Language
Override mechanism to specify the natural language, if it is
different from that reported in the "attributes-natural-language"
operation attribute of the response. The IPP object MAY use the
Natural Language Override mechanism redundantly, i.e., use it even
when the value is in the same natural language as the value
supplied in the "attributes-natural-language" operation attribute
of the response.
An IPP object MUST NOT reject a request based on a supplied
natural language in an "attributes-natural-language" operation
attribute or in any attribute that uses the Natural Language
Override.
Note: Supplying 'text' or 'name' attributes with an incompatible
combination of natural language and charset can cause undesired
behavior. For example, suppose a Printer supports charsets
'utf-8', 'iso-8859-1', and 'iso-8859-7'. Suppose also that it
supports natural languages 'en' (English), 'fr' (French), and 'el'
(Greek). Although the Printer supports the charset 'iso-8859-1'
and natural language 'el', it probably does not support the
combination of Greek text strings using the 'iso-8859-1' charset.
The Printer handles this apparent incompatibility differently,
depending on the context in which it occurs:
* In a Job Creation request: If the Client supplies a 'text' or
'name' attribute (for example, the "job-name" operation
attribute) that uses an apparently incompatible combination, it
is a Client choice that does not affect the Printer or its
correct operation. Therefore, the Printer simply accepts the
Client-supplied value, stores it with the Job, and responds
back with the same combination whenever the Client (or any
Client) queries for that attribute.
* In a query-type operation, like Get-Printer-Attributes: If the
Client requests an apparently incompatible combination, the
Printer responds (as described in Section 4.1.4.2) using the
Printer's configured natural language rather than the natural
language requested by the Client.
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In either case, the Printer does not reject the request because of
the apparent incompatibility. The potential incompatible
combination of charset and natural language can occur either at
the global operation level or at the Natural Language Override
attribute-by-attribute level. In addition, since the response
always includes explicit charset and natural language information,
there is never any question or ambiguity in how the Client
interprets the response.
4.1.4.2. Response Operation Attributes
The Printer MUST supply and the Client MUST support the following
REQUIRED operation attributes in every IPP/1.1 operation response:
"attributes-charset" (charset):
This operation attribute identifies the charset used by any 'text'
and 'name' attributes that the Printer object is returning in this
response. The value in this response MUST be the same value as
the "attributes-charset" operation attribute supplied by the
Client in the request. If this is not possible (i.e., the charset
requested is not supported), the request would have been rejected.
See "attributes-charset" described in Section 4.1.4.1 above.
If the Printer object supports more than just the 'utf-8' charset,
the Printer object MUST be able to perform code conversion between
each of the charsets supported on a "highest fidelity possible"
basis in order to return the 'text' and 'name' attributes in the
charset requested by the Client. However, some information loss
can occur during the charset conversion, depending on the charsets
involved. For example, depending on implementation, the Printer
object can convert from a UTF-8 'a' to a US-ASCII 'a' (with no
loss of information); from an ISO Latin 1 CAPITAL LETTER A WITH
ACUTE ACCENT to US-ASCII 'A' (losing the accent); or from a UTF-8
Japanese Kanji character to some ISO Latin 1 error character
indication such as '?', a decimal code equivalent, or the absence
of a character.
Whether an implementation that supports more than one charset
stores the data in the charset supplied by the Client or performs
code conversion to one of the other supported charsets depends on
implementation. The strategy should try to minimize loss of
information during code conversion. On each response, such an
implementation converts from its internal charset to that
requested.
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"attributes-natural-language" (naturalLanguage):
This operation attribute identifies the natural language used by
any 'text' and 'name' attributes that the IPP object is returning
in this response. Unlike the "attributes-charset" operation
attribute, the IPP object MAY return the natural language of the
Job object or the Printer's configured natural language as
identified by the Printer's "natural-language-configured"
attribute, rather than the natural language supplied by the
Client. For any 'text' or 'name' attribute or status message in
the response that is in a different natural language than the
value returned in the "attributes-natural-language" operation
attribute, the IPP object MUST use the Natural Language Override
mechanism (see Sections 5.1.2.2 and 5.1.3.2) on each attribute
value returned. The IPP object MAY use the Natural Language
Override mechanism redundantly, i.e., use it even when the value
is in the same natural language as the value supplied in the
"attributes-natural-language" operation attribute of the response.
4.1.5. Operation Targets
All IPP operations are directed at IPP objects. For Printer
operations, the operation is always directed at a Printer object
using one of its URIs, i.e., one of the values in the Printer's
"printer-uri-supported" attribute. Even if the Printer object
supports more than one URI, the Client supplies only one URI as the
target of the operation. The Client identifies the target object by
supplying the correct URI in the "printer-uri" operation attribute.
For Job operations, the operation is directed at either:
o The Printer object that created the Job object using the Printer
object's URI and the Job's numeric identifier (Job ID). Since the
Printer object that created the Job object generated the Job ID,
it MUST be able to correctly associate the Client-supplied Job ID
with the correct Job object. The Client supplies the Printer's
URI in the "printer-uri" operation attribute and the Job ID in the
"job-id" operation attribute.
o The Job object itself using the Job's URI. In this case, the
Client identifies the target object by supplying the correct URI
in the "job-uri" (uri) operation attribute (Section 5.3.2).
Clients SHOULD send the "printer-uri" and "job-id" operation
attributes in Job operations.
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If the operation is directed at the Job object directly using the
Job's URI, the Client MUST NOT include the redundant "job-id"
operation attribute.
The operation target attributes are REQUIRED operation attributes
that are included in every operation request. Like the charset and
natural language attributes (see Section 4.1.4), the operation target
attributes are specially ordered operation attributes. In all cases,
the operation target attributes immediately follow the
"attributes-charset" and "attributes-natural-language" attributes
within the Operation Attributes group; however, the specific ordering
rules are as follows:
o In the case where there is only one operation target attribute
(i.e., either only the "printer-uri" attribute or only the
"job-uri" attribute), that attribute MUST be the third attribute
in the Operation Attributes group.
o In the case where Job operations use two operation target
attributes (i.e., the "printer-uri" and "job-id" attributes), the
"printer-uri" attribute MUST be the third attribute and the
"job-id" attribute MUST be the fourth attribute.
In all cases, the target URIs contained within the body of IPP
operation requests and responses MUST be in absolute format rather
than relative format (a relative URL identifies a resource with the
scope of the HTTP server, but does not include scheme, host,
or port).
The following rules apply to the use of port numbers in URIs that
identify IPP objects:
1. If the URI scheme allows the port number to be explicitly
included in the URI string, and a port number is specified within
the URI, then that port number MUST be used by the Client to
contact the IPP object.
2. If the URI scheme allows the port number to be explicitly
included in the URI string, and a port number is not specified
within the URI, then the default port number implied by that URI
scheme MUST be used by the Client to contact the IPP object.
3. If the URI scheme does not allow an explicit port number to be
specified within the URI, then the default port number implied by
that URI MUST be used by the Client to contact the IPP object.
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Note: "Internet Printing Protocol/1.1: IPP URL Scheme" [RFC3510] and
"Internet Printing Protocol (IPP) over HTTPS Transport Binding and
the 'ipps' URI Scheme" [RFC7472] define the mapping of IPP onto HTTP
and HTTPS, respectively, and define and register a default port
number.
4.1.6. Operation Response Status-Code Values and Status Messages
Every operation response includes a REQUIRED "status-code" parameter,
SHOULD include the "status-message" operation attribute, and MAY
include the "detailed-status-message" operation attribute. The
Print-URI and Send-URI response MAY also include the
"document-access-error" operation attribute.
4.1.6.1. "status-code" (type2 enum)
The REQUIRED "status-code" parameter provides information on the
processing of a request.
The status-code is intended for use by automata. A Client
implementation of IPP SHOULD convert status-code values into any
localized message that has semantic meaning to the End User.
The "status-code" value is a numeric value that has semantic meaning.
The "status-code" syntax is similar to a "type2 enum" (see
Section 5.1 ("Attribute Syntaxes")), except that values can range
only from 0x0000 to 0x7fff. Appendix B describes and assigns the
status-code values, and suggests a corresponding status message for
each status-code for use by the Client when the user's natural
language is English.
If the Printer performs an operation with no errors and it encounters
no problems, it MUST return the status-code 'successful-ok' in the
response. See Appendix B.
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If the Client supplies unsupported values for the following
parameters or operation attributes, the Printer object MUST reject
the operation, MAY return the unsupported attribute value in the
Unsupported Attributes group, and MUST return the indicated
status-code:
+---------------------+---------------------------------------------+
| Parameter/Attribute | Status-Code |
+---------------------+---------------------------------------------+
| version-number | server-error-version-not-supported |
+---------------------+---------------------------------------------+
| operation-id | server-error-operation-not-supported |
+---------------------+---------------------------------------------+
| attributes-charset | client-error-charset-not-supported |
+---------------------+---------------------------------------------+
| compression | client-error-compression-not-supported |
+---------------------+---------------------------------------------+
| document-format | client-error-document-format-not-supported |
+---------------------+---------------------------------------------+
| document-uri | client-error-uri-scheme-not-supported, |
| | client-error-document-access-error |
+---------------------+---------------------------------------------+
Table 1: Status-Code Values for All Requests
If the Client supplies unsupported values for other attributes, or
unsupported attributes, the Printer returns the status-code defined
in Section 4.1.7 ("Unsupported Attributes").
4.1.6.2. "status-message" (text(255))
The RECOMMENDED "status-message" operation attribute provides a short
textual description of the status of the operation. The
"status-message" attribute's syntax is "text(255)", so the maximum
length is 255 octets (see Section 5.1.2). The status message is
intended for the human End User. If a response does include a
"status-message" attribute, an IPP Client can examine or display the
messages in some implementation-specific manner. The
"status-message" attribute is especially useful for a later version
of a Printer to return as supplemental information for the human
user, to accompany a status-code that an earlier version of a Client
might not understand.
If the Printer supports the "status-message" operation attribute, it
MUST be able to generate this message in any of the natural languages
identified by the Printer's "generated-natural-language-supported"
attribute and MUST honor any supported value for the
"attributes-natural-language" operation attribute (Section 4.1.4.1)
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of the Client request. Appendix B suggests the text for the status
message returned by the Printer for use with the English natural
language.
As described in Section 4.1.4.1, for any returned 'text' attribute,
if there is a choice for generating this message, the Printer uses
the natural language indicated by the value of
"attributes-natural-language" in the Client request, if supported;
otherwise, the Printer uses the value in the Printer's own
"natural-language-configured" attribute.
If the Printer supports the "status-message" operation attribute, it
SHOULD use the REQUIRED 'utf-8' charset to return a status message
for the following error status-code values (see Appendix B):
'client-error-bad-request', 'client-error-charset-not-supported',
'server-error-internal-error',
'server-error-operation-not-supported', and
'server-error-version-not-supported'. In this case, it MUST set the
value of the "attributes-charset" operation attribute to 'utf-8' in
the error response.
4.1.6.3. "detailed-status-message" (text(MAX))
The OPTIONAL "detailed-status-message" operation attribute provides
additional more-detailed technical and implementation-specific
information about the operation for Administrators or other
experienced technical people. The "detailed-status-message"
attribute's syntax is "text(MAX)", so the maximum length is
1023 octets (see Section 5.1.2). If the Printer supports the
"detailed-status-message" operation attribute, the Printer SHOULD
localize the message, unless such localization would obscure the
technical meaning of the message. Clients MUST NOT attempt to parse
the value of this attribute. See the "document-access-error"
operation attribute (Section 4.1.6.4) for additional errors that a
program can process.
4.1.6.4. "document-access-error" (text(MAX))
This OPTIONAL operation attribute provides additional information
about any Document access errors encountered by the Printer before it
returned a response to the Print-URI (Section 4.2.2) or Send-URI
(Section 4.3.2) operation. For errors in the protocol identified by
the URI scheme in the "document-uri" operation attribute, such as
'http:' or 'ftp:', the error code is returned in parentheses,
followed by the URI. For example:
(404) http://www.example.com/filename.pdf
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Most Internet protocols use decimal error codes (unlike IPP), so the
ASCII error code representation is in decimal.
4.1.7. Unsupported Attributes
The Unsupported Attributes group contains attributes that are not
supported by the operation. This group is primarily for the Job
Creation operations, but all operations can return this group.
A Printer MUST include an Unsupported Attributes group in a response
if the status-code is one of the following:
'successful-ok-ignored-or-substituted-attributes',
'successful-ok-conflicting-attributes',
'client-error-attributes-or-values-not-supported', or
'client-error-conflicting-attributes'.
If the status-code is one of the four specified in the preceding
paragraph, the Unsupported Attributes group MUST contain all of those
attributes and only those attributes that are:
a. an operation or Job Template attribute supplied in the request,
and
b. unsupported by the Printer. See below for details on the three
categories of "unsupported" attributes.
If the status-code is one of those in Table 1 in Section 4.1.6.1, the
OPTIONAL Unsupported Attributes group contains the unsupported
parameter or attribute indicated in that table.
If the Printer is not returning any unsupported attributes in the
response, the Printer SHOULD omit the Unsupported Attributes group
rather than sending an empty group. However, a Client MUST be able
to accept an empty group.
Unsupported attributes fall into three categories:
1. The Printer does not support the supplied attribute (no matter
what the attribute syntax or value).
2. The Printer does support the attribute, but it does not support
some or all of the particular attribute syntaxes or values
supplied by the Client, i.e., the Printer does not have those
attribute syntaxes or values in its corresponding "xxx-supported"
attribute.
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3. The Printer does support the attributes and values supplied, but
the particular values are in conflict with one another, because
they violate a constraint, such as not being able to staple
transparencies.
In the case of an unsupported attribute name, the Printer returns the
Client-supplied attribute with a substituted value of 'unsupported'.
This value's syntax type is "out-of-band", and its encoding is
defined by special rules for "out-of-band" values in the Encoding and
Transport document [RFC8010]. Its value indicates no support for the
attribute itself -- see the beginning of Section 5.1 in this
document.
In the case of a supported attribute with one or more unsupported
attribute syntaxes or values, the Printer simply returns the
Client-supplied attribute with the unsupported attribute syntaxes or
values as supplied by the Client. This indicates support for the
attribute but no support for that particular attribute syntax or
value. If the Client supplies a multi-valued attribute with more
than one value and the Printer supports the attribute but only
supports a subset of the Client-supplied attribute syntaxes or
values, the Printer MUST return only those attribute syntaxes or
values that are unsupported.
In the case of two (or more) supported attribute values that are in
conflict with one another (although each is supported independently,
the values conflict when requested together within the same Job), the
Printer MUST return all the values that it ignores or substitutes to
resolve the conflict but not any of the values that it is still
using. The choice for exactly how to resolve the conflict is
implementation dependent. See Section 4.2.1.2 and Appendix C. See
the Implementor's Guides [RFC3196] [PWG5100.19] for examples.
4.1.8. Versions
Each operation request and response carries with it a
"version-number" parameter. Each value of the "version-number"
parameter is in the form "X.Y" where X is the major version number
and Y is the minor version number. By including a version number in
the Client request, it allows the Client to identify which version of
IPP it is interested in using, i.e., the version whose conformance
requirements the Client can depend upon the Printer to meet.
If the IPP object does not support that major version number supplied
by the Client, i.e., the "major version number" portion of the
"version-number" parameter does not match any of the values of the
Printer's "ipp-versions-supported" attribute (see Section 5.4.14),
the object MUST respond with a status-code of
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'server-error-version-not-supported' along with the closest version
number that is supported (see Appendix B.1.5.4). If the major
version number is supported but the minor version number is not, the
IPP object SHOULD accept the request and attempt to perform it (or
reject the request if the operation is not supported); otherwise, it
rejects the request and returns the
'server-error-version-not-supported' status-code. In all cases, the
IPP object MUST return the "version-number" value that it supports
that is closest to the version number supplied by the Client in the
request.
There is no version negotiation per se. However, if a Client has
received a 'server-error-version-not-supported' status-code from an
IPP object, the Client SHOULD try again with a different version
number. A Client MAY also determine the versions supported either
from a directory that conforms to Appendix D or by querying the
Printer's "ipp-versions-supported" attribute (see Section 5.4.14) to
determine which versions are supported.
An IPP/1.1 object implementation MUST support version '1.1', i.e.,
meet the conformance requirements for IPP/1.1 as specified in this
document and [RFC8010]. IPP implementations SHOULD accept any
request with the major version '1' or '2', or reject the request if
the operation is not supported.
There is only one notion of "version number" that covers both IPP
Model and IPP protocol changes. Changes to the major version number
of the Model and Semantics document can indicate structural or
syntactic changes that make it impossible for older versions of IPP
Clients and Printers to correctly parse and correctly process the new
or changed attributes, operations, and responses. If the major
version number changes, the minor version number is set to zero. As
an example, adding the REQUIRED "ipp-attribute-fidelity" attribute to
version '1.1' (if it had not been part of version '1.0') would have
required a change to the major version number, since an IPP/1.0
Printer would not have processed a request with the correct semantics
that contained the "ipp-attribute-fidelity" attribute that it did not
know about. Items that might affect the changing of the major
version number include any changes to the Model and Semantics
document (this document) or the Encoding and Transport document
[RFC8010] itself, such as:
o reordering of ordered attributes or attribute sets
o changes to the syntax of existing attributes
o adding REQUIRED (for an IPP object to support) Operation
Attributes groups
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o adding values to existing REQUIRED operation attributes
o adding REQUIRED operations
Changes to the minor version number indicate the addition of new
features, attributes, and attribute values that might not be
understood by all IPP objects but that can be ignored if not
understood. Items that might affect the changing of the minor
version number include any changes to the model objects and
attributes but not the encoding and transport rules [RFC8010] (except
adding attribute syntaxes). Examples of such changes are:
o grouping all extensions not included in a previous version into a
new version
o adding new attribute values
o adding new object attributes
o adding OPTIONAL (for an IPP object to support) operation
attributes (i.e., those attributes that an IPP object can ignore
without confusing Clients)
o adding OPTIONAL (for an IPP object to support) Operation
Attributes groups (i.e., those attributes that an IPP object can
ignore without confusing Clients)
o adding new attribute syntaxes
o adding OPTIONAL operations
o changing Job attributes or Printer attributes from OPTIONAL to
REQUIRED or vice versa
o adding OPTIONAL attribute syntaxes to an existing attribute
The encoding [RFC8010] of the "version-number" parameter MUST NOT
change over any version number (either major or minor). This rule
guarantees that all future versions will be backwards compatible with
all previous versions (at least for checking the "version-number"
parameter). In addition, any protocol elements (attributes, error
codes, tags, etc.) that are not carried forward from one version to
the next are DEPRECATED so that they can never be reused with new
semantics.
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Implementations that support a certain version SHOULD support all
previous Standards Track versions. As each new version is defined
(through the release of a new IPP specification document), that
version will specify which previous versions MUST and which versions
SHOULD be supported in compliant implementations.
4.1.9. Job Creation Operations
In order to "submit a Print Job" and create a new Job, a Client
issues a Job Creation request. A Job Creation request is any one of
the following three operation requests:
o The Print-Job Request: A Client that wants to submit a Print Job
with only a single Document can use the Print-Job operation. The
operation allows for the Client to "push" the Document data to the
Printer by including the Document data in the request itself.
Note that Clients SHOULD instead use the Create-Job and
Send-Document requests, if supported by the Printer, since they
allow for Job monitoring and control during submission of the
Document data.
o The Print-URI Request: A Client that wants to submit a Print Job
with only a single Document (where the Printer "pulls" the
Document data instead of the Client "pushing" the data to the
Printer) uses the Print-URI operation. In this case, the Client
includes in the request only a URI reference to the Document data
(not the Document data itself).
o The Create-Job Request: A Client that wants to submit a Print Job
with zero or more Documents uses the Create-Job operation. This
operation is followed by an arbitrary number of Send-Document
and/or Send-URI operations, each creating another Document for the
newly created Job. The Send-Document operation includes the
Document data in the request (the Client "pushes" the Document
data to the Printer), and the Send-URI operation includes only a
URI reference to the Document data in the request (the Printer
"pulls" the Document data from the referenced location). The last
Send-Document or Send-URI request for a given Job includes a
"last-document" operation attribute set to 'true' indicating that
this is the last request.
Throughout this document, the term "Job Creation request" is used to
refer to any of these three operation requests.
A Create-Job operation followed by only one Send-Document operation
is semantically equivalent to a Print-Job operation; however, the
Client SHOULD use the Create-Job and Send-Document operations (when
supported) for all Jobs with a single Document to allow for reliable
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Job control and monitoring. Print-Job is a REQUIRED operation (all
implementations MUST support it), whereas Create-Job is a RECOMMENDED
operation and hence some implementations might not support it.
Job submission time is the point in time when a Client issues a Job
Creation request. The initial state of every Job is the 'pending',
'pending-held', or 'processing' state (see Section 5.3.7). When the
Printer begins processing the Print Job, the Job's state moves to
'processing'. This is known as Job processing time.
At Job submission time and at the time a Validate-Job operation is
received, the Printer MUST do the following:
1. Process the Client-supplied attributes and either accept or
reject the request
2. Validate the syntax of and support for the scheme of any
Client-supplied URI
At Job submission time, the Printer MUST validate whether the
supplied attributes, attribute syntaxes, and values are supported by
matching them with the Printer's corresponding "xxx-supported"
attributes. See Section 4.1.7 for details. See the Implementor's
Guides [RFC3196] [PWG5100.19] for guidance on processing Job Creation
requests.
At Job submission time, the Printer MAY perform the validation checks
reserved for Job processing time, such as:
1. Validating the format of the Document data
2. Validating the actual contents of any Client-supplied URI
(resolve the reference and follow the link to the Document data)
At Job submission time, these additional Job processing time
validation checks are essentially useless, since they require
actually parsing and interpreting the Document data, are not
guaranteed to be 100% accurate, and MUST be done, yet again, at Job
processing time. Also, in the case of a URI, checking for
availability at Job submission time does not guarantee availability
at Job processing time. In addition, at Job processing time, the
Printer might discover any of the following conditions that were not
detectable at Job submission time:
o runtime errors in the Document data,
o nested Document data that is in an unsupported format,
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o the URI reference is no longer valid (i.e., the server hosting the
Document might be down), or
o any other Job processing error.
At Job submission time, a Printer, especially a non-spooling Printer,
MAY accept Jobs for which it does not have enough space. In such a
situation, a Printer MAY stop reading data from a Client for an
indefinite period of time. A Client MUST be prepared for a write
operation to block for an indefinite period of time (see Section 6.1
("Client Conformance Requirements")).
When a Printer has too little space for starting a new Job, it MAY
reject a new Job Creation request. In this case, a Printer MUST
return a response (in reply to the rejected request) with a
status-code of 'server-error-busy' (see Appendix B.1.5.8), and it MAY
close the connection before receiving all bytes of the operation. A
Printer SHOULD indicate that it is temporarily unable to accept Jobs
by setting the 'spool-space-full' value in its
"printer-state-reasons" attribute and removing the value when it can
accept another Job (see Section 5.4.12).
When receiving a 'server-error-busy' status-code in an operation
response, a Client MUST be prepared for the Printer to close the
connection before the Client has sent all of the data (especially for
the Print-Job operation). A Client MUST be prepared to keep
submitting a Job Creation request until the Printer accepts the Job
Creation request.
At Job processing time, since the Printer has already responded with
a successful status-code in the response to the Job Creation request,
if the Printer detects an error, the Printer is unable to inform the
End User of the error with an operation status-code. In this case,
the Printer, depending on the error, can set the Job's "job-state",
"job-state-reasons", and/or "job-state-message" attributes to the
appropriate value(s) so that later queries can report the correct Job
status.
Note: Asynchronous notification of events is defined in "Internet
Printing Protocol (IPP): Event Notifications and Subscriptions"
[RFC3995].
4.2. Printer Operations
All Printer operations are directed at Printers. A Client MUST
always supply the "printer-uri" operation attribute in order to
identify the correct target of the operation.
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4.2.1. Print-Job Operation
This REQUIRED operation allows a Client to submit a Print Job with
only one Document and supply the Document data (rather than just a
reference to the data). See Appendix C for the suggested steps for
processing Job Creation requests and their operation and Job Template
attributes.
4.2.1.1. Print-Job Request
The following groups of attributes are supplied as part of the
Print-Job request:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.1. The Printer MUST
copy these values to the corresponding Job Status attributes
described in Sections 5.3.19 and 5.3.20.
Target:
The "printer-uri" (uri) operation attribute, which is the
target for this operation as described in Section 4.1.5.
Requesting User Name:
The "requesting-user-name" (name(MAX)) attribute SHOULD be
supplied by the Client as described in Section 9.3.
"job-name" (name(MAX)):
The Client MAY supply and the Printer MUST support this
attribute. It contains the Client-supplied Job name. If this
attribute is supplied by the Client, its value is used for the
"job-name" attribute of the newly created Job. The Client MAY
automatically include any information that will help the
End User distinguish amongst his/her Jobs, such as the name of
the application program along with information from the
Document, such as the Document name, Document subject, or
source file name. If this attribute is not supplied by the
Client, the Printer generates a name to use in the "job-name"
attribute of the newly created Job (see Section 5.3.5).
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"ipp-attribute-fidelity" (boolean):
The Client MAY supply and the Printer MUST support this
attribute. The value 'true' indicates that total fidelity to
Client-supplied Job Template attributes and values is required;
otherwise, the Printer MUST reject the Print-Job request. The
value 'false' indicates that a reasonable attempt to print the
Job is acceptable and the Printer MUST accept the Print-Job
request. If not supplied, the Printer assumes that the value
is 'false'. All Printers MUST support both types of Job
processing. See Appendix C for a full description of
"ipp-attribute-fidelity" and its relationship to other
attributes, especially the Printer's "pdl-override-supported"
attribute.
"document-name" (name(MAX)):
The Client MAY supply and the Printer MUST support this
attribute. It contains the Client-supplied Document name. The
Document name MAY be different than the Job name. Typically,
the Client software automatically supplies the Document name on
behalf of the End User by using a file name or an
application-generated name. If this attribute is supplied, its
value can be used in a manner defined by each implementation.
Examples include the following: printed along with the Job (Job
start sheet, page adornments, etc.), used by accounting or
resource-tracking management tools, or even stored along with
the Document as a Document-level attribute.
"compression" (type2 keyword):
The Client MAY supply and the Printer MUST support this
attribute. The Client-supplied "compression" operation
attribute identifies the compression algorithm used on the
Document data. The following cases exist:
a. If the Client omits this attribute, the Printer MUST assume
that the data is not compressed, i.e., the Printer follows
the rules below as if the Client supplied the "compression"
attribute with a value of 'none'.
b. If the Client supplies this attribute but the value is not
supported by the Printer, i.e., the value is not one of the
values of the Printer's "compression-supported" attribute,
the Printer MUST reject the request and return the
'client-error-compression-not-supported' status-code. See
Section 4.1.7 for details on returning unsupported
attributes and values.
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c. If the Client supplies the attribute and the Printer
supports the attribute value, the Printer uses the
corresponding decompression algorithm on the Document data.
d. If the decompression algorithm fails before the Printer
returns an operation response, the Printer MUST reject the
request and return the 'client-error-compression-error'
status-code.
e. If the decompression algorithm fails after the Printer
returns an operation response, the Printer MUST abort the
Job and add the 'compression-error' value to the Job's
"job-state-reasons" attribute.
f. If the decompression algorithm succeeds, the Document data
MUST then have the format specified by the Job's
"document-format" attribute, if supplied (see the
"document-format" operation attribute definition below).
"document-format" (mimeMediaType):
The Client MAY supply and the Printer MUST support this
attribute. The value identifies the format of the supplied
Document data. The following cases exist:
a. If the Client does not supply this attribute, the Printer
assumes that the Document data is in the format defined by
the Printer's "document-format-default" attribute (i.e.,
the Printer follows the rules below as if the Client
supplied the "document-format" attribute with a value equal
to the Printer's default value).
b. If the Client supplies this attribute but the value is not
supported by the Printer, i.e., the value is not one of the
values of the Printer's "document-format-supported"
attribute, the Printer MUST reject the request and return
the 'client-error-document-format-not-supported'
status-code.
c. If the Client supplies this attribute and its value is
'application/octet-stream' (i.e., to be auto-sensed; see
Section 5.1.10.1), and the format is not one of the
Document formats that the Printer can auto-sense, and this
check occurs before the Printer returns an operation
response, then the Printer MUST reject the request and
return the 'client-error-document-format-not-supported'
status-code.
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d. If the Client supplies this attribute and the value is
supported by the Printer, the Printer is capable of
interpreting the Document data.
e. If interpretation of the Document data fails before the
Printer returns an operation response, the Printer MUST
reject the request and return the
'client-error-document-format-error' status-code.
f. If interpretation of the Document data fails after the
Printer returns an operation response, the Printer MUST
abort the Job and add the 'document-format-error' value to
the Job's "job-state-reasons" attribute.
"document-natural-language" (naturalLanguage):
The Client MAY supply and the Printer SHOULD support this
attribute. The value specifies the natural language of the
Document content for those Document formats that require a
specification of the natural language in order to properly
image the Document.
"job-k-octets" (integer(0:MAX)):
The Client MAY supply and the Printer SHOULD support this
attribute. The Client-supplied "job-k-octets" operation
attribute identifies the total size of the Document(s) in
K octets being submitted (see Section 5.3.17.1 for the complete
semantics). If the Client supplies the attribute and the
Printer supports the attribute, the value of the attribute is
used to populate the Job's "job-k-octets" Job Description
attribute.
For this attribute and the following two attributes
("job-impressions" and "job-media-sheets"), if the Client
supplies the attribute but the Printer does not support the
attribute, the Printer ignores the Client-supplied value. If
the Client supplies the attribute and the Printer supports the
attribute, and the value is within the range of the
corresponding Printer's "xxx-supported" attribute, the Printer
MUST use the value to populate the Job's "xxx" attribute. If
the Client supplies the attribute and the Printer supports the
attribute, but the value is outside the range of the
corresponding Printer's "xxx-supported" attribute, the Printer
MUST copy the attribute and its value to the Unsupported
Attributes group, reject the request, and return the
'client-error-attributes-or-values-not-supported' status-code.
If the Client does not supply the attribute, the Printer SHOULD
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populate the corresponding Job attribute if it supports the
attribute and is able to calculate or discern the correct
value.
"job-impressions" (integer(0:MAX)):
The Client MAY supply and the Printer SHOULD support this
attribute. The Client-supplied "job-impressions" operation
attribute identifies the total size in number of Impressions of
the Document(s) being submitted (see Section 5.3.17.2 for the
complete semantics).
See the last paragraph under "job-k-octets".
"job-media-sheets" (integer(1:MAX)):
The Client MAY supply and the Printer SHOULD support this
attribute. The Client-supplied "job-media-sheets" operation
attribute identifies the total number of Media Sheets to be
produced for this Job (see Section 5.3.17.3 for the complete
semantics).
See the last paragraph under "job-k-octets".
Group 2: Job Template Attributes
The Client MAY supply a set of Job Template attributes as defined
in Section 5.2. If the Client is not supplying any Job Template
attributes in the request, the Client SHOULD omit Group 2 rather
than sending an empty group. However, a Printer MUST be able to
accept an empty group.
Group 3: Document Data
The Client MUST supply the Document data to be processed.
The simplest Print-Job request consists of just the
"attributes-charset" and "attributes-natural-language" operation
attributes, the "printer-uri" target operation attribute, and the
Document data. In this simple case, the Printer:
o creates a new Job containing a single Document,
o stores a generated Job name in the "job-name" attribute in the
natural language and charset requested (see Section 4.1.4.1) (if
those are supported; otherwise, using the Printer's default
natural language and charset), and
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o at Job processing time, uses its corresponding default value
attributes for the supported Job Template attributes that were not
supplied by the Client as an IPP attribute or embedded
instructions in the Document data.
4.2.1.2. Print-Job Response
The Printer MUST return to the Client the following sets of
attributes as part of the Print-Job response:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.2.
Status Message:
In addition to the REQUIRED status-code returned in every
response, the response MAY include a "status-message"
(text(255)) and/or a "detailed-status-message" (text(MAX))
operation attribute as described in Appendix B and
Section 4.1.6. If the Client supplies unsupported or
conflicting Job Template attributes or values, the Printer MUST
reject or accept the Print-Job request, depending on whether
the Client supplied a 'true' or 'false' value for the
"ipp-attribute-fidelity" operation attribute. See the
Implementor's Guides [RFC3196] [PWG5100.19] for guidance on
processing Job Creation requests.
Group 2: Unsupported Attributes
See Section 4.1.7 for details on returning unsupported attributes.
The value of "ipp-attribute-fidelity" supplied by the Client does
not affect what attributes the Printer returns in this group. The
value of "ipp-attribute-fidelity" only affects whether the
Print-Job operation is accepted or rejected. If the Job is
accepted, the Client can query the Job using the
Get-Job-Attributes operation, requesting the unsupported
attributes that were returned in the Print-Job response to see
which attributes were ignored (not stored in the Job) and which
attributes were stored with other (substituted) values.
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Group 3: Job Attributes
"job-id" (integer(1:MAX)):
The Printer MUST return the Job's ID in the REQUIRED "job-id"
Job attribute. The Client uses this "job-id" attribute in
conjunction with the "printer-uri" attribute used in the
Print-Job request when directing Job operations at the Printer.
"job-uri" (uri):
The Printer MUST return the Job's URI by returning the contents
of the REQUIRED "job-uri" Job attribute.
"job-state" (type1 enum):
The Printer MUST return the Job's REQUIRED "job-state"
attribute. The value of this attribute along with the value of
the "job-state-reasons" attribute is a "snapshot" of the new
Job's state when the Printer returns the response.
"job-state-reasons" (1setOf type2 keyword):
The Printer MUST return the Job's REQUIRED "job-state-reasons"
attribute.
"job-state-message" (text(MAX)):
The Printer SHOULD return the Job's RECOMMENDED
"job-state-message" attribute. If the Printer supports this
attribute, then it MUST be returned in the response. If this
attribute is not returned in the response, the Client can
assume that the "job-state-message" attribute is not supported
and will not be returned in a subsequent Job query.
"number-of-intervening-jobs" (integer(0:MAX)):
The Printer SHOULD return the Job's RECOMMENDED
"number-of-intervening-jobs" attribute. If the Printer
supports this attribute, then it MUST be returned in the
response. If this attribute is not returned in the response,
the Client can assume that the "number-of-intervening-jobs"
attribute is not supported and will not be returned in a
subsequent Job query.
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Note: Since any Printer state information that affects a Job's state
is reflected in the "job-state" and "job-state-reasons" attributes,
it is sufficient to return only these attributes and no additional
Printer Status attributes.
Note: The simplest response consists of just the "attributes-charset"
and "attributes-natural-language" operation attributes and the
"job-uri", "job-id", and "job-state" Job attributes. In this
simplest case, the status-code is 'successful-ok' and there is no
"status-message" or "detailed-status-message" operation attribute.
4.2.2. Print-URI Operation
This OPTIONAL operation is identical to the Print-Job operation
(Section 4.2.1), except that a Client supplies a URI reference to the
Document data using the "document-uri" (uri) operation attribute (in
Group 1) rather than including the Document data itself. Before
returning the response, the Printer MUST validate that the Printer
supports the retrieval method (e.g., 'http', 'ftp', etc.) implied by
the URI and MUST check for valid URI syntax. If the Client-supplied
URI scheme is not supported, i.e., the value is not in the Printer's
"referenced-uri-scheme-supported" attribute, the Printer MUST reject
the request and return the 'client-error-uri-scheme-not-supported'
status-code.
The Printer MAY validate the accessibility of the Document as part of
the operation, or subsequently. If the Printer discovers an
accessibility problem before returning an operation response, it MUST
reject the request and return the
'client-error-document-access-error' status-code. The Printer MAY
also return a specific Document access error code using the
"document-access-error" operation attribute (see Section 4.1.6.4).
If the Printer discovers this Document accessibility problem after
accepting the request and returning an operation response with one of
the successful status-code values, the Printer MUST add the
"document-access-error" value to the Job's "job-state-reasons"
attribute and MAY populate the Job's "job-document-access-errors" Job
Status attribute (see Section 5.3.11). See the Implementor's Guides
[RFC3196] [PWG5100.19] for guidance on processing Job Creation
requests.
If the Printer supports this operation, it MUST support the
"reference-uri-schemes-supported" Printer attribute (see
Section 5.4.27).
It is up to the Printer to interpret the URI and subsequently "pull"
the Document data from the source referenced by the URI string.
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4.2.3. Validate-Job Operation
This REQUIRED operation is similar to the Print-Job operation
(Section 4.2.1), except that a Client supplies no Document data and
the Printer allocates no resources, i.e., it does not create a new
Job. This operation is used only to verify the capabilities of a
Printer against whatever attributes are supplied by the Client in the
Validate-Job request. By using the Validate-Job operation, a Client
can validate that an identical Job Creation request (with the
Document data) would be accepted. The Validate-Job operation also
performs the same security negotiation as the Print-Job, Print-URI,
and Create-Job operations (see Section 9) so that a Client can check
that the Client and Printer security requirements can be met before
performing a Job Creation request.
The Validate-Job operation does not accept a "document-uri" attribute
in order to allow a Client to check that the same Print-URI operation
will be accepted, since the Client doesn't send the data with the
Print-URI operation. The Client SHOULD just issue the Print-URI
request.
The Printer returns the same status-code values, Operation Attributes
(Group 1), and Unsupported Attributes (Group 2) as the Print-Job
operation. However, no Job Attributes (Group 3) are returned, since
no Job is created.
4.2.4. Create-Job Operation
This RECOMMENDED operation is similar to the Print-Job operation
(Section 4.2.1), except that in the Create-Job request, a Client does
not supply Document data or any reference to Document data. Also,
the Client does not supply any of the "document-name",
"document-format", "compression", or "document-natural-language"
operation attributes. This operation is followed by one or more
Send-Document or Send-URI operations. In each of those operation
requests, the Client MAY supply the "document-name",
"document-format", and "document-natural-language" attributes for
each Document in the Job.
If a Printer supports the Create-Job operation, it MUST also support
the Send-Document operation. If the Printer supports the Create-Job
and Print-URI operations, it MUST also support the Send-URI
operation.
If the Printer supports this operation, it MUST support the
"multiple-operation-time-out" Printer attribute (see Section 5.4.31).
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If the Printer supports this operation, then it MUST support the
"multiple-document-jobs-supported" Printer Description attribute
(see Section 5.4.16) and indicate whether it supports multiple
Documents in a Job.
If the Printer supports this operation and supports multiple
Documents in a Job, then it MUST support the
"multiple-document-handling" Job Template attribute with at least
one value (see Section 5.2.4), and the associated
"multiple-document-handling-default" and
"multiple-document-handling-supported" Printer attributes
(see Section 5.2).
After the Create-Job operation has completed, the value of the
"job-state" attribute is similar to the "job-state" after a Print-Job
operation, even though no Document data has arrived. A Printer MAY
set the 'job-data-insufficient' value of the Job's
"job-state-reasons" attribute to indicate that processing cannot
begin until sufficient data has arrived and set the "job-state" to
either 'pending' or 'pending-held'. A non-spooling Printer that
doesn't implement the 'pending' Job state can set "job-state" to
'processing', even though there is not yet any data to process.
See Sections 5.3.7 and 5.3.8.
4.2.5. Get-Printer-Attributes Operation
This REQUIRED operation allows a Client to request the values of the
attributes of a Printer. In the request, the Client supplies the set
of Printer attribute names and/or attribute group names in which the
requester is interested. In the response, the Printer returns a
corresponding attribute set with the appropriate attribute values
filled in.
For Printers, the possible names of attribute groups are:
o 'job-template': the subset of the Job Template attributes that
apply to a Printer (the last two columns of Table 8 in
Section 5.2) that the implementation supports for Printers.
o 'printer-description': the subset of the attributes specified in
Section 5.4 that the implementation supports for Printers.
o 'all': the special group 'all' that includes all attributes that
the implementation supports for Printers.
Since a Client MAY request specific attributes or named groups, there
is a potential for some overlap. For example, if a Client requests
'printer-name' and 'all', the Client is actually requesting the
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"printer-name" attribute twice: once by naming it explicitly, and
once by inclusion in the 'all' group. In such cases, the Printer
returns each attribute only once in the response even if it is
requested multiple times. The Client SHOULD NOT request the same
attribute in multiple ways.
Printers MUST support all group names and MUST return all supported
attributes belonging to the group.
4.2.5.1. Get-Printer-Attributes Request
The following sets of attributes are part of the
Get-Printer-Attributes request:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.1.
Target:
The "printer-uri" (uri) operation attribute, which is the
target for this operation as described in Section 4.1.5.
Requesting User Name:
The "requesting-user-name" (name(MAX)) attribute SHOULD be
supplied by the Client as described in Section 9.3.
"requested-attributes" (1setOf keyword):
The Client MAY supply a set of attribute names and/or attribute
group names in whose values the requester is interested. The
Printer MUST support this attribute. If the Client omits this
attribute, the Printer MUST respond as if this attribute had
been supplied with a value of 'all'.
"document-format" (mimeMediaType):
The Client MAY supply and the Printer MUST support this
attribute. It is useful for a Client to determine the set of
supported attribute values that relate to the requested
Document format. The Printer MUST return the attributes and
values that it uses to validate a Job in a Job Creation or
Validate-Job operation in which this Document format is
supplied. The Printer SHOULD return only (1) those attributes
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that are supported for the specified format and (2) the
attribute values that are supported for the specified Document
format. By specifying the Document format, the Client can get
the Printer to eliminate the attributes and values that are not
supported for a specific Document format. For example, a
Printer might have multiple interpreters to support both
'application/postscript' (for PostScript) and 'text/plain' (for
text) Documents. However, only one of those interpreters might
support the "number-up" Job Template attribute with values of
'1', '2', and '4'. The other interpreter might only be able to
support the "number-up" Job Template attribute with a value of
'1'. Thus, a Client can use the Get-Printer-Attributes
operation to obtain the attributes and values that will be used
to accept/reject a Job Creation request.
If the Printer does not distinguish between different sets of
supported values for each different Document format when
validating Jobs in the Create-Job, Print-Job, Print-URI, and
Validate-Job operations, it MUST NOT distinguish between
different Document formats in the Get-Printer-Attributes
operation. If the Printer does distinguish between different
sets of supported values for each different Document format
specified by the Client, this specialization applies only to
the following Printer attributes:
+ Printer attributes that are Job Template attributes
("xxx-default", "xxx-supported", and "xxx-ready")
(see Table 8 in Section 5.2),
+ "pdl-override-supported",
+ "compression-supported",
+ "job-k-octets-supported",
+ "job-impressions-supported,
+ "job-media-sheets-supported",
+ "printer-driver-installer",
+ "color-supported", and
+ "reference-uri-schemes-supported"
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The values of all other Printer attributes (including
"document-format-supported") remain invariant with respect to
the Client-supplied Document format (except for new Printer
Description attributes as registered according to Section 7.2).
If the Client omits this "document-format" operation attribute,
the Printer MUST respond as if the attribute had been supplied
with the value of the Printer's "document-format-default"
attribute. Clients SHOULD always supply a value for
"document-format", since the Printer's
"document-format-default" value can be
'application/octet-stream', in which case the returned
attributes and values are for the union of the Document formats
that the Printer can automatically sense. For more details,
see the description of the 'mimeMediaType' attribute syntax in
Section 5.1.10.
If the Client supplies a value for the "document-format"
operation attribute that is not supported by the Printer, i.e.,
is not among the values of the Printer's
"document-format-supported" attribute, the Printer MUST reject
the operation and return the
'client-error-document-format-not-supported' status-code.
4.2.5.2. Get-Printer-Attributes Response
The Printer returns the following sets of attributes as part of the
Get-Printer-Attributes response:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.2.
Status Message:
In addition to the REQUIRED status-code returned in every
response, the response MAY include a "status-message"
(text(255)) and/or a "detailed-status-message" (text(MAX))
operation attribute as described in Appendix B and
Section 4.1.6.
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Group 2: Unsupported Attributes
See Section 4.1.7 for details on returning unsupported attributes.
The response MAY contain the "requested-attributes" operation
attribute with any supplied values (attribute keywords) that were
requested by the Client but are not supported by the Printer. If
the Printer does return unsupported attributes referenced in the
"requested-attributes" operation attribute and that attribute
included group names, such as 'all', the unsupported attributes
MUST NOT include attributes described in this document but not
supported by the implementation.
Group 3: Printer Attributes
This is the set of requested attributes and their current values.
The Printer ignores (does not respond with) any requested
attribute that is not supported. The Printer MAY respond with a
subset of the supported attributes and values, depending on the
security policy in force. However, the Printer MUST respond with
the 'unknown' value for any supported attribute (including all
REQUIRED attributes) for which the Printer does not know the
value. Also, the Printer MUST respond with 'no-value' for any
supported attribute (including all REQUIRED attributes) for which
the Administrator has not configured a value. See the description
of the "out-of-band" values in the beginning of Section 5.1.
4.2.6. Get-Jobs Operation
This REQUIRED operation allows a Client to retrieve the list of Jobs
belonging to the target Printer. The Client can also supply a list
of Job attribute names and/or attribute group names. A group of Job
attributes will be returned for each Job that is returned.
This operation is similar to the Get-Job-Attributes operation, except
that this Get-Jobs operation returns attributes from possibly more
than one Job.
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4.2.6.1. Get-Jobs Request
The Client submits the Get-Jobs request to a Printer.
The following groups of attributes are part of the Get-Jobs request:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.1.
Target:
The "printer-uri" (uri) operation attribute, which is the
target for this operation as described in Section 4.1.5.
Requesting User Name:
The "requesting-user-name" (name(MAX)) attribute SHOULD be
supplied by the Client as described in Section 9.3.
"limit" (integer(1:MAX)):
The Client MAY supply and the Printer MUST support this
attribute. It is an integer value that determines the maximum
number of Jobs that a Client will receive from the Printer even
if "which-jobs" or "my-jobs" (described below) constrain which
Jobs are returned. The limit is a "stateless limit" in that if
the value supplied by the Client is 'N', then only the first
'N' Jobs are returned in the Get-Jobs response. If the Client
does not supply this attribute, the Printer responds with all
applicable Jobs.
"requested-attributes" (1setOf type2 keyword):
The Client MAY supply and the Printer MUST support this
attribute. It is a set of Job attribute names and/or attribute
group names in whose values the requester is interested. This
set of attributes is returned for each Job that is returned.
The allowed attribute group names are the same as those defined
in the Get-Job-Attributes operation in Section 4.3.4. If the
Client does not supply this attribute, the Printer MUST respond
as if the Client had supplied this attribute with two values:
"job-uri" and "job-id".
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"which-jobs" (type2 keyword):
The Client MAY supply and the Printer MUST support this
attribute. It indicates which Jobs MUST be returned by the
Printer. The values for this attribute include:
+ 'completed': Any Job whose state is 'completed', 'canceled',
or 'aborted'.
+ 'not-completed': Any Job whose state is 'pending',
'processing', 'processing-stopped', or 'pending-held'.
A Printer MUST support both values. However, if the
implementation does not keep Jobs in the 'completed',
'canceled', and 'aborted' states, then it returns no Jobs when
the 'completed' value is supplied.
If a Client supplies some other value that is not supported by
the Printer, the Printer MUST copy the attribute and the
unsupported value to the Unsupported Attributes group, reject
the request, and return the
'client-error-attributes-or-values-not-supported' status-code.
If the Client does not supply this attribute, the Printer MUST
respond as if the Client had supplied the attribute with a
value of 'not-completed'.
"my-jobs" (boolean):
The Client MAY supply and the Printer MUST support this
attribute. It indicates whether Jobs from all users or just
the Jobs submitted by the requesting user of this request MUST
be considered as candidate Jobs to be returned by the Printer.
If the Client does not supply this attribute, the Printer MUST
respond as if the Client had supplied the attribute with a
value of 'false', i.e., Jobs from all users. The means for
authenticating the requesting user and matching the Jobs is
described in Section 9.
4.2.6.2. Get-Jobs Response
The Printer returns all of the Jobs up to the number specified by the
"limit" attribute that match the criteria as defined by the attribute
values supplied by the Client in the request. It is possible that no
Jobs are returned, since there can literally be no Jobs at the
Printer or there can be no Jobs that match the criteria supplied by
the Client. If the Client requests any Job attributes at all, there
is a set of Job Attributes returned for each Job.
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It is not an error for the Printer to return 0 Jobs. If the response
returns 0 Jobs because there are no Jobs matching the criteria, and
the request would have returned one or more Jobs with a status-code
of 'successful-ok' if there had been Jobs matching the criteria, then
the status-code for 0 Jobs MUST be 'successful-ok'.
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.2.
Status Message:
In addition to the REQUIRED status-code returned in every
response, the response MAY include a "status-message"
(text(255)) and/or a "detailed-status-message" (text(MAX))
operation attribute as described in Appendix B and
Section 4.1.6.
Group 2: Unsupported Attributes
See Section 4.1.7 for details on returning unsupported attributes.
The response MAY contain the "requested-attributes" operation
attribute with any supplied values (attribute keywords) that were
requested by the Client but are not supported by the Printer. If
the Printer does return unsupported attributes referenced in the
"requested-attributes" operation attribute and that attribute
included group names, such as 'all', the unsupported attributes
MUST NOT include attributes described in this document but not
supported by the implementation.
Groups 3 to N: Job Attributes
The Printer responds with one set of Job Attributes for each
returned Job. The Printer ignores (does not respond with) any
requested attribute or value that is not supported or that is
restricted by the security policy in force, including whether the
requesting user is the user that submitted the Job
(Job-originating user) or not (see Section 9). However, the
Printer MUST respond with the 'unknown' value for any supported
attribute (including all REQUIRED attributes) for which the
Printer does not know the value, unless it would violate the
security policy. See the description of the "out-of-band" values
in the beginning of Section 5.1.
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Jobs are returned in the following order:
* If the Client requests all 'completed' Jobs (Jobs in the
'completed', 'aborted', or 'canceled' states), then the Jobs
are returned newest to oldest (with respect to actual
completion time).
* If the Client requests all 'not-completed' Jobs (Jobs in the
'pending', 'processing', 'pending-held', and
'processing-stopped' states), then Jobs are returned in
relative chronological order of expected time to complete
(based on whatever scheduling algorithm is configured for the
Printer).
4.2.7. Pause-Printer Operation
This OPTIONAL operation allows a Client to stop the Printer from
scheduling Jobs on all its devices. Depending on implementation, the
Pause-Printer operation MAY also stop the Printer from processing the
current Job or Jobs. Any Job that is currently being printed is
either (1) stopped as soon as the implementation permits or
(2) completed, depending on implementation. The Printer MUST still
accept Job Creation requests to create new Jobs but MUST prevent any
Jobs from entering the 'processing' state.
If the Pause-Printer operation is supported, then the Resume-Printer
operation MUST be supported, and vice versa.
The IPP Printer stops the current Job(s) on its device or devices
that were in the 'processing' or 'processing-stopped' state as soon
as the implementation permits. If the implementation will take
appreciable time to stop, the IPP Printer adds the 'moving-to-paused'
value to the Printer's "printer-state-reasons" attribute (see
Section 5.4.12). When the device or devices have all stopped, the
IPP Printer transitions the Printer to the 'stopped' state; removes
the 'moving-to-paused' value, if present; and adds the 'paused' value
to the Printer's "printer-state-reasons" attribute.
When the current Job or Jobs complete that were in the 'processing'
state, the IPP Printer transitions them to the 'completed' state.
When the current Job or Jobs stop in mid-processing that were in the
'processing' state, the IPP Printer transitions them to the
'processing-stopped' state and adds the 'printer-stopped' value to
the Jobs' "job-state-reasons" attribute.
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For any Jobs that are 'pending' or 'pending-held', the
'printer-stopped' value of the Jobs' "job-state-reasons" attribute
also applies. However, the IPP Printer MAY update those Jobs'
"job-state-reasons" values when those Jobs are queried (so-called
"lazy evaluation").
The IPP Printer MUST accept the request in any state and transition
the Printer to the indicated new "printer-state" before returning, as
shown in Table 2.
Access Rights: The authenticated user (see Section 9.3) performing
this operation MUST be an Operator or Administrator of the Printer
(see Sections 1 and 9.5). Otherwise, the IPP Printer MUST reject the
operation and return 'client-error-forbidden',
'client-error-not-authenticated', or 'client-error-not-authorized'
as appropriate.
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+--------------+--------------+-----------------+-------------------+
| Current | New | "printer-state- | IPP Printer's |
| "printer- | "printer- | reasons" | response status- |
| state" | state" | | code and action: |
+--------------+--------------+-----------------+-------------------+
| 'idle' | 'stopped' | 'paused' | 'successful-ok' |
+--------------+--------------+-----------------+-------------------+
| 'processing' | 'processing' | 'moving-to- | Option 1: |
| | | paused' | 'successful-ok'; |
| | | | Later, when all |
| | | | output has |
| | | | stopped, the |
| | | | "printer-state" |
| | | | becomes |
| | | | 'stopped', and |
| | | | the 'paused' |
| | | | value replaces |
| | | | the 'moving-to- |
| | | | paused' value in |
| | | | the "printer- |
| | | | state-reasons" |
| | | | attribute |
+--------------+--------------+-----------------+-------------------+
| 'processing' | 'stopped' | 'paused' | Option 2: |
| | | | 'successful-ok'; |
| | | | all device output |
| | | | stopped |
| | | | immediately |
+--------------+--------------+-----------------+-------------------+
| 'stopped' | 'stopped' | 'paused' | 'successful-ok' |
+--------------+--------------+-----------------+-------------------+
Table 2: Pause-Printer State Transitions
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4.2.7.1. Pause-Printer Request
The following groups of attributes are part of the Pause-Printer
request:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.1.
Target:
The "printer-uri" (uri) operation attribute, which is the
target for this operation as described in Section 4.1.5.
Requesting User Name:
The "requesting-user-name" (name(MAX)) attribute SHOULD be
supplied by the Client as described in Section 9.3.
4.2.7.2. Pause-Printer Response
The following groups of attributes are part of the Pause-Printer
response:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.2.
Status Message:
In addition to the REQUIRED status-code returned in every
response, the response MAY include a "status-message"
(text(255)) and/or a "detailed-status-message" (text(MAX))
operation attribute as described in Appendix B and
Section 4.1.6.
Group 2: Unsupported Attributes
See Section 4.1.7 for details on returning unsupported attributes.
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4.2.8. Resume-Printer Operation
This OPTIONAL operation allows a Client to resume the Printer
scheduling Jobs on all its devices. The Printer MUST remove the
'paused' and 'moving-to-paused' values from the Printer's
"printer-state-reasons" attribute, if present. If there are no other
reasons to keep a device paused (such as a media jam), the IPP
Printer is free to transition itself to the 'processing' or 'idle'
state, depending on whether there are Jobs to be processed or not,
respectively, and the device(s) resumes processing Jobs.
If the Pause-Printer operation is supported, then the Resume-Printer
operation MUST be supported, and vice versa.
The IPP Printer removes the 'printer-stopped' value from any Job's
"job-state-reasons" attributes contained in that Printer.
The IPP Printer MUST accept the request in any state and transition
the Printer to the indicated new state as shown in Table 3.
Access Rights: The authenticated user (see Section 9.3) performing
this operation MUST be an Operator or Administrator of the Printer
(see Sections 1 and 9.5). Otherwise, the IPP Printer MUST reject the
operation and return 'client-error-forbidden',
'client-error-not-authenticated', or 'client-error-not-authorized'
as appropriate.
The Resume-Printer request and Resume-Printer response have the same
attribute groups and attributes as the Pause-Printer operation (see
Sections 4.2.7.1 and 4.2.7.2).
+-----------------+-----------------+-------------------------------+
| Current | New "printer- | IPP Printer's response |
| "printer-state" | state" | status-code and action: |
+-----------------+-----------------+-------------------------------+
| 'idle' | 'idle' | 'successful-ok' |
+-----------------+-----------------+-------------------------------+
| 'processing' | 'processing' | 'successful-ok' |
+-----------------+-----------------+-------------------------------+
| 'stopped' | 'processing' | 'successful-ok', when there |
| | | are Jobs to be processed |
+-----------------+-----------------+-------------------------------+
| 'stopped' | 'idle' | 'successful-ok', when there |
| | | are no Jobs to be processed |
+-----------------+-----------------+-------------------------------+
Table 3: Resume-Printer State Transitions
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4.2.9. Purge-Jobs Operation
This DEPRECATED operation allows a Client to remove all Jobs from a
Printer, regardless of their Job states, including Jobs in the
Printer's Job History (see Section 5.3.7.2). After a Purge-Jobs
operation has been performed, a Printer MUST return no Jobs in
subsequent Get-Job-Attributes and Get-Jobs responses (until new Jobs
are submitted).
Note: This operation SHOULD NOT be supported in new implementations,
since it destroys Printer accounting information.
Whether the Purge-Jobs (and Get-Jobs) operation affects Jobs that
were submitted to the device from sources other than the IPP Printer
in the same way that the Purge-Jobs operation affects Jobs that were
submitted to the IPP Printer using IPP depends on implementation,
i.e., on whether IPP is being used as a universal management protocol
or just to manage IPP Jobs, respectively.
Note: If an Operator wants to cancel all Jobs without clearing out
the Job History, the Operator uses the Cancel-Job operation on each
Job instead of using the Purge-Jobs operation.
If this OPTIONAL operation is supported, the Printer MUST accept this
operation in any state and transition the Printer to the 'idle'
state.
Access Rights: The authenticated user (see Section 9.3) performing
this operation MUST be an Operator or Administrator of the Printer
(see Sections 1 and 9.5). Otherwise, the Printer MUST reject the
operation and return 'client-error-forbidden',
'client-error-not-authenticated', and 'client-error-not-authorized'
as appropriate.
The Purge-Jobs request and Purge-Jobs response have the same
attribute groups and attributes as the Pause-Printer operation (see
Sections 4.2.7.1 and 4.2.7.2).
4.3. Job Operations
All Job operations are directed at Jobs. A Client MUST always supply
some means of identifying the Job object in order to identify the
correct target of the operation. That Job identification SHOULD be
the combination of a Printer URI with a Job ID but MAY be the
(single) Job URI. The IPP implementation MUST support both forms of
identification for every Job.
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4.3.1. Send-Document Operation
This RECOMMENDED operation allows a Client to add a Document to a Job
that was created using the Create-Job operation. In the Create-Job
response, the Printer returns the Job's URI (the "job-uri" attribute)
and the Job's 32-bit identifier (the "job-id" attribute). For each
new Document that the Client desires to add, the Client uses a
Send-Document operation. Each Send-Document request contains the
entire stream of Document data for one Document.
If the Printer supports this operation but does not support multiple
Documents per Job, the Printer MUST reject subsequent Send-Document
operations supplied with data and return the
'server-error-multiple-document-jobs-not-supported' status-code.
However, the Printer MUST accept the first Document with a 'true' or
'false' value for the "last-document" operation attribute (see
below), so that Clients MAY always submit one Document Job with a
'false' value for "last-document" in the first Send-Document and a
'true' value for "last-document" in the second Send-Document (with
no data).
Since the Create-Job and the send operations (Send-Document or
Send-URI operations) that follow could occur over an arbitrarily long
period of time for a particular Job, a Client MUST send another send
operation within a minimum time interval, as defined by the IPP
Printer, after the receipt of the previous request for the Job. If a
Printer supports the Create-Job and Send-Document operations, the
Printer MUST support the "multiple-operation-time-out" attribute (see
Section 5.4.31). This attribute indicates the minimum number of
seconds the Printer will wait for the next send operation before
taking some recovery action.
A Printer MUST recover from an errant Client that does not supply a
send operation, sometime after the minimum time interval specified by
the Printer's "multiple-operation-time-out" attribute. Such recovery
MAY include any of the following actions or other recovery actions:
1. Assume that the Job is an invalid Job, start the process of
changing the Job state to 'aborted', add the 'aborted-by-system'
value to the Job's "job-state-reasons" attribute (see
Section 5.3.8), and clean up all resources associated with the
Job. In this case, if another send operation is finally
received, the Printer responds with a 'client-error-not-possible'
or 'client-error-not-found' status-code, depending on whether the
Job is still around when the send operation finally arrives.
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2. Assume that the last send operation received was in fact the last
Document (as if the "last-document" flag had been set to 'true'),
close the Job, and proceed to process it (i.e., move the Job's
state to 'pending').
3. Assume that the last send operation received was in fact the last
Document and close the Job, but move it to the 'pending-held'
state and add the 'submission-interrupted' value to the Job's
"job-state-reasons" attribute (see Section 5.3.8). This action
allows the user or an Operator to determine whether to continue
processing the Job by moving it back to the 'pending' state using
the Release-Job operation (see Section 4.3.6) or to cancel the
Job using the Cancel-Job operation (see Section 4.3.3).
Each implementation is free to decide the "best" action to take,
depending on the following: local policy, whether any Documents have
been added, whether the implementation spools Jobs or not, and/or any
other piece of information available to it. If the choice is to
abort the Job, it is possible that the Job has already been processed
to the point that some Media Sheet pages have been printed.
Access Rights: The authenticated user (see Section 9.3) performing
this operation must be either the Job owner (as determined in the
Create-Job operation) or an Operator or Administrator of the Printer
(see Sections 1 and 9.5). Otherwise, the Printer MUST reject the
operation and return 'client-error-forbidden',
'client-error-not-authenticated', or 'client-error-not-authorized'
as appropriate.
4.3.1.1. Send-Document Request
The following attribute sets are part of the Send-Document request:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.1.
Target:
Either the "printer-uri" (uri) plus "job-id" (integer(1:MAX)),
or the "job-uri" (uri) operation attribute(s), which define the
target for this operation as described in Section 4.1.5.
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Requesting User Name:
The "requesting-user-name" (name(MAX)) attribute SHOULD be
supplied by the Client as described in Section 9.3.
"document-name" (name(MAX)):
The Client MAY supply and the Printer MUST support this
attribute. It contains the Client-supplied Document name. The
Document name MAY be different than the Job name and is not
guaranteed to be unique across multiple Documents in the same
Job. Typically, the Client software automatically supplies the
Document name on behalf of the End User by using a file name or
an application-generated name. See the description of the
"document-name" operation attribute in the Print-Job request
(Section 4.2.1.1) for more information about this attribute.
"compression" (type2 keyword):
See the description of "compression" for the Print-Job
operation in Section 4.2.1.1.
"document-format" (mimeMediaType):
See the description of "document-format" for the Print-Job
operation in Section 4.2.1.1.
"document-natural-language" (naturalLanguage):
The Client MAY supply and the Printer MAY support this
attribute. It specifies the natural language of the Document
content for those Document formats that require a specification
of the natural language in order to properly image the
Document.
"last-document" (boolean):
The Client MUST supply and the Printer MUST support this
attribute. It is a boolean flag that is set to 'true' if this
is the last Document for the Job; otherwise, it is set to
'false'.
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Group 2: Document Data
The Client MUST supply the Document data if the "last-document"
flag is set to 'false'. However, since a Client might not know
that the previous Document sent with a Send-Document (or Send-URI)
operation was the last Document (i.e., the "last-document"
attribute was set to 'false'), it is legal to send a Send-Document
request with no Document data where the "last-document" flag is
set to 'true'. Such a request MUST NOT increment the value of the
Job's "number-of-documents" attribute, since no real Document was
added to the Job. It is not an error for a Client to submit a Job
with no actual Document data, i.e., only a single Create-Job and
Send-Document request with a "last-document" operation attribute
set to 'true' with no Document data.
4.3.1.2. Send-Document Response
The following sets of attributes are part of the Send-Document
response:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.2.
Status Message:
In addition to the REQUIRED status-code returned in every
response, the response MAY include a "status-message"
(text(255)) and/or a "detailed-status-message" (text(MAX))
operation attribute as described in Appendix B and
Section 4.1.6.
Group 2: Unsupported Attributes
See Section 4.1.7 for details on returning unsupported attributes.
Group 3: Job Object Attributes
This is the same set of attributes as those described in the
Print-Job response (see Section 4.2.1.2).
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4.3.2. Send-URI Operation
This RECOMMENDED operation is identical to the Send-Document
operation (see Section 4.3.1), except that a Client MUST supply a URI
reference ("document-uri" operation attribute) rather than the
Document data itself. If a Printer supports this operation, Clients
can use both Send-URI and Send-Document operations to add new
Documents to an existing Job. However, if a Client needs to indicate
that the previous Send-URI or Send-Document was the last Document,
the Client MUST use the Send-Document operation with no Document data
and the "last-document" flag set to 'true' (rather than using a
Send-URI operation with no "document-uri" operation attribute).
If a Printer supports this operation, it MUST also support the
Print-URI operation (see Section 4.2.2).
The Printer MUST validate the syntax and URI scheme of the supplied
URI before returning a response, just as in the Print-URI operation.
The Printer MAY validate the accessibility of the Document as part of
the operation, or subsequently (see Section 4.2.2).
4.3.3. Cancel-Job Operation
This REQUIRED operation allows a Client to cancel a Print Job from
the time the Job is created up to the time it is completed, canceled,
or aborted. Since a Job might already be printing by the time a
Cancel-Job is received, some Media Sheet pages might be printed
before the Job is actually terminated.
The Printer MUST accept or reject the request based on the Job's
current state and transition the Job to the indicated new state as
shown in Table 4.
Access Rights: The authenticated user (see Section 9.3) performing
this operation must be either the Job owner or an Operator or
Administrator of the Printer (see Sections 1 and 9.5). Otherwise,
the Printer MUST reject the operation and return
'client-error-forbidden', 'client-error-not-authenticated', or
'client-error-not-authorized' as appropriate.
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+-------------------+--------------------+--------------------------+
| Current "job- | New "job-state" | Printer's response |
| state" | | status-code and action: |
+-------------------+--------------------+--------------------------+
| 'pending' | 'canceled' | 'successful-ok' |
+-------------------+--------------------+--------------------------+
| 'pending-held' | 'canceled' | 'successful-ok' |
+-------------------+--------------------+--------------------------+
| 'processing' | 'canceled' | 'successful-ok' |
+-------------------+--------------------+--------------------------+
| 'processing' | 'processing' | 'successful-ok' (note 1) |
+-------------------+--------------------+--------------------------+
| 'processing' | 'processing' | 'client-error-not- |
| | | possible' (note 2) |
+-------------------+--------------------+--------------------------+
| 'processing- | 'canceled' | 'successful-ok' |
| stopped' | | |
+-------------------+--------------------+--------------------------+
| 'processing- | 'processing- | 'successful-ok' (note 1) |
| stopped' | stopped' | |
+-------------------+--------------------+--------------------------+
| 'processing- | 'processing- | 'client-error-not- |
| stopped' | stopped' | possible' (note 2) |
+-------------------+--------------------+--------------------------+
| 'completed' | 'completed' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
| 'canceled' | 'canceled' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
| 'aborted' | 'aborted' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
Table 4: Cancel-Job State Transitions
Note 1: If the implementation requires some measurable time to cancel
the Job in the 'processing' or 'processing-stopped' Job state, the
Printer MUST add the 'processing-to-stop-point' value to the Job's
"job-state-reasons" attribute and then transition the Job to the
'canceled' state when the processing ceases (see Section 5.3.8).
Note 2: If the Job already has the 'processing-to-stop-point' value
in its "job-state-reasons" attribute, then the Printer MUST reject a
Cancel-Job operation.
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4.3.3.1. Cancel-Job Request
The following groups of attributes are part of the Cancel-Job
request:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.1.
Target:
Either the "printer-uri" (uri) plus "job-id" (integer(1:MAX)),
or the "job-uri" (uri) operation attribute(s), which define the
target for this operation as described in Section 4.1.5.
Requesting User Name:
The "requesting-user-name" (name(MAX)) attribute SHOULD be
supplied by the Client as described in Section 9.3.
"message" (text(127)):
The Client MAY supply and the Printer MAY support this
attribute. It is a message to the Operator. This "message"
attribute is not the same as the "job-message-from-operator"
attribute. That attribute is used to report a message from the
Operator to the End User that queries that attribute. This
"message" operation attribute is used to send a message from
the Client to the Operator along with the operation request.
How or where to display this message to the Operator (if
at all) is an implementation decision.
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4.3.3.2. Cancel-Job Response
The following sets of attributes are part of the Cancel-Job response:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.2.
Status Message:
In addition to the REQUIRED status-code returned in every
response, the response MAY include a "status-message"
(text(255)) and/or a "detailed-status-message" (text(MAX))
operation attribute as described in Appendix B and
Section 4.1.6.
Group 2: Unsupported Attributes
See Section 4.1.7 for details on returning unsupported attributes.
Once a successful response has been sent, the implementation
guarantees that the Job will eventually end up in the 'canceled'
state. Between the time that the Cancel-Job operation is accepted
and when the Job enters the 'canceled' job-state (see
Section 5.3.7), the "job-state-reasons" attribute SHOULD contain
the 'processing-to-stop-point' value, which indicates to later
queries that although the Job might still be 'processing' it will
eventually end up in the 'canceled' state, not the 'completed'
state.
4.3.4. Get-Job-Attributes Operation
This REQUIRED operation allows a Client to request the values of
attributes of a Job, and it is almost identical to the
Get-Printer-Attributes operation (see Section 4.2.5). The only
differences are that the operation is directed at a Job rather than a
Printer, there is no "document-format" operation attribute used when
querying a Job, and the returned attribute group is a set of Job
attributes rather than a set of Printer attributes.
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For Jobs, the possible names of attribute groups are:
o 'job-template': the subset of the Job Template attributes that
apply to a Job (the first column of Table 8 in Section 5.2) that
the implementation supports for Jobs.
o 'job-description': the subset of the Job Description and Status
attributes specified in Section 5.3 that the implementation
supports for Jobs.
o 'all': the special group 'all' that includes all attributes that
the implementation supports for Jobs.
Since a Client MAY request specific attributes or named groups, there
is a potential for some overlap. For example, if a Client requests
'job-name' and 'job-description', the Client is actually requesting
the "job-name" attribute once by naming it explicitly, and once by
inclusion in the 'job-description' group. In such cases, the Printer
returns the attribute only once in the response even if it is
requested multiple times. The Client SHOULD NOT request the same
attribute in multiple ways.
Jobs MUST support all group names and MUST return all supported
attributes belonging to the group.
4.3.4.1. Get-Job-Attributes Request
The following groups of attributes are part of the Get-Job-Attributes
request when the request is directed at a Job:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.1.
Target:
Either the "printer-uri" (uri) plus "job-id" (integer(1:MAX)),
or the "job-uri" (uri) operation attribute(s), which define the
target for this operation as described in Section 4.1.5.
Requesting User Name:
The "requesting-user-name" (name(MAX)) attribute SHOULD be
supplied by the Client as described in Section 9.3.
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"requested-attributes" (1setOf keyword):
The Client MAY supply and the Printer MUST support this
attribute. It is a set of attribute names and/or attribute
group names in whose values the requester is interested. If
the Client omits this attribute, the Printer MUST respond as if
this attribute had been supplied with a value of 'all'.
4.3.4.2. Get-Job-Attributes Response
The Printer returns the following sets of attributes as part of the
Get-Job-Attributes response:
Group 1: Operation Attributes
Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language"
attributes as described in Section 4.1.4.2.
"attributes-natural-language" MAY be the natural language of
the Job, rather than the one requested.
Status Message:
In addition to the REQUIRED status-code returned in every
response, the response MAY include a "status-message"
(text(255)) and/or a "detailed-status-message" (text(MAX))
operation attribute as described in Appendix B and
Section 4.1.6.
Group 2: Unsupported Attributes
See Section 4.1.7 for details on returning unsupported attributes.
The response MAY contain the "requested-attributes" operation
attribute with any supplied values (attribute keywords) that were
requested by the Client but are not supported by the Printer. If
the Printer does return unsupported attributes referenced in the
"requested-attributes" operation attribute and that attribute
included group names, such as 'all', the unsupported attributes
MUST NOT include attributes described in this document but not
supported by the implementation.
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Group 3: Job Attributes
This is the set of requested attributes and their current values.
The Printer ignores (does not respond with) any requested
attribute or value that is not supported or that is restricted by
the security policy in force, including whether the requesting
user is the user that submitted the Job (Job-originating user) or
not (see Section 9). However, the Printer MUST respond with the
'unknown' value for any supported attribute (including all
REQUIRED attributes) for which the Printer does not know the
value, unless it would violate the security policy. See the
description of the "out-of-band" values in the beginning of
Section 5.1.
4.3.5. Hold-Job Operation
This OPTIONAL operation allows a Client to hold a pending Job in the
queue so that it is not eligible for scheduling. If the Hold-Job
operation is supported, then the Release-Job operation MUST be
supported, and vice versa. The OPTIONAL "job-hold-until" operation
attribute allows a Client to specify whether to hold the Job
indefinitely or until a specified time period, if supported.
The Printer MUST accept or reject the request based on the Job's
current state and transition the Job to the indicated new state as
shown in Table 5.
Note: In order to keep the Hold-Job operation simple, such a request
is rejected when the Job is in the 'processing' or
'processing-stopped' state. If an operation is needed to hold Jobs
while in either of these states, it will be added as an additional
operation, rather than overloading the Hold-Job operation. Then it
is clear to Clients by querying the Printer's "operations-supported"
(see Section 5.4.15) and the Job's "job-state" (see Section 5.3.7)
attributes which operations are possible.
Access Rights: The authenticated user (see Section 9.3) performing
this operation must be either the Job owner or an Operator or
Administrator of the Printer (see Sections 1 and 9.5). Otherwise,
the Printer MUST reject the operation and return
'client-error-forbidden', 'client-error-not-authenticated', or
'client-error-not-authorized' as appropriate.
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+-------------------+--------------------+--------------------------+
| Current "job- | New "job-state" | Printer's response |
| state" | | status-code and action: |
+-------------------+--------------------+--------------------------+
| 'pending' | 'pending-held' | 'successful-ok' (note 1) |
+-------------------+--------------------+--------------------------+
| 'pending' | 'pending' | 'successful-ok' (note 2) |
+-------------------+--------------------+--------------------------+
| 'pending-held' | 'pending-held' | 'successful-ok' (note 1) |
+-------------------+--------------------+--------------------------+
| 'pending-held' | 'pending' | 'successful-ok' (note 2) |
+-------------------+--------------------+--------------------------+
| 'processing' | 'processing' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
| 'processing- | 'processing- | 'client-error-not- |
| stopped' | stopped' | possible' |
+-------------------+--------------------+--------------------------+
| 'completed' | 'completed' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
| 'canceled' | 'canceled' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
| 'aborted' | 'aborted' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
Table 5: Hold-Job State Transitions
Note 1: If the implementation supports multiple reasons for a Job to
be in the 'pending-held' state, the Printer MUST add the
"job-hold-until-specified" value to the Job's "job-state-reasons"
attribute.
Note 2: If the Printer supports the "job-hold-until" operation
attribute, but the specified time period has already started (or is
the 'no-hold' value) and there are no other reasons to hold the Job,
the Printer MUST make the Job be a candidate for processing
immediately (see Section 5.2.2) by putting the Job in the 'pending'
state.
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4.3.5.1. Hold-Job Request
The groups and operation attributes are the same as those defined for
a Cancel-Job request (see Section 4.3.3.1), with the addition of the
following Group 1 operation attribute:
"job-hold-until" (type2 keyword | name(MAX)):
The Client MAY supply and the Printer MUST support this operation
attribute in a Hold-Job request if it supports the
"job-hold-until" Job Template attribute in Job Creation requests.
See Section 5.2.2. The Printer SHOULD support the
"job-hold-until" Job Template attribute for use in Job Creation
requests with at least the 'indefinite' value, if it supports the
Hold-Job operation. Otherwise, a Client cannot create a Job and
hold it immediately (without picking some supported time period in
the future).
If supplied and supported as specified in the Printer's
"job-hold-until-supported" attribute, the Printer copies the
supplied operation attribute to the Job, replacing the Job's
previous "job-hold-until" attribute, if present, and makes the Job
a candidate for scheduling during the supplied named time period.
If supplied but either the "job-hold-until" operation attribute
itself or the value supplied is not supported, the Printer accepts
the request, returns the unsupported attribute or value in the
Unsupported Attributes group according to Section 4.1.7, returns
the 'successful-ok-ignored-or-substituted-attributes' status-code,
and holds the Job indefinitely until a Client performs a
subsequent Release-Job operation.
If (1) the Client supplies either a value that specifies a time
period that has already started or the 'no-hold' value (meaning
don't hold the Job) and (2) the Printer supports the
"job-hold-until" operation attribute and there are no other
reasons to hold the Job, the Printer MUST accept the operation and
make the Job be a candidate for processing immediately (see
Section 5.2.2).
If the Client does not supply a "job-hold-until" operation
attribute in the request, the Printer MUST populate the Job with a
"job-hold-until" attribute with the 'indefinite' value (if the
Printer supports the "job-hold-until" attribute) and hold the Job
indefinitely, until a Client performs a Release-Job operation.
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4.3.5.2. Hold-Job Response
The groups and attributes are the same as those defined for a
Cancel-Job response (see Section 4.3.3.2).
4.3.6. Release-Job Operation
This OPTIONAL operation allows a Client to release a previously held
Job so that it is again eligible for scheduling. If the Hold-Job
operation is supported, then the Release-Job operation MUST be
supported, and vice versa.
This operation removes the "job-hold-until" Job attribute, if
present, from the Job that had been supplied in the Create-Job or
most recent Hold-Job or Restart-Job operation and removes its effect
on the Job. The Printer MUST remove the "job-hold-until-specified"
value from the Job's "job-state-reasons" attribute, if present. See
Section 5.3.8.
The Printer MUST accept or reject the request based on the Job's
current state and transition the Job to the indicated new state as
shown in Table 6.
Access Rights: The authenticated user (see Section 9.3) performing
this operation must be either the Job owner or an Operator or
Administrator of the Printer (see Sections 1 and 9.5). Otherwise,
the Printer MUST reject the operation and return
'client-error-forbidden', 'client-error-not-authenticated', or
'client-error-not-authorized' as appropriate.
The Release-Job request and Release-Job response have the same
attribute groups and attributes as the Cancel-Job operation (see
Sections 4.3.3.1 and 4.3.3.2).
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+-------------------+--------------------+--------------------------+
| Current "job- | New "job-state" | Printer's response |
| state" | | status-code and action: |
+-------------------+--------------------+--------------------------+
| 'pending' | 'pending' | 'successful-ok'. No |
| | | effect on the Job. |
+-------------------+--------------------+--------------------------+
| 'pending-held' | 'pending-held' | 'successful-ok' (note 1) |
+-------------------+--------------------+--------------------------+
| 'pending-held' | 'pending' | 'successful-ok' |
+-------------------+--------------------+--------------------------+
| 'processing' | 'processing' | 'successful-ok'. No |
| | | effect on the Job. |
+-------------------+--------------------+--------------------------+
| 'processing- | 'processing- | 'successful-ok'. No |
| stopped' | stopped' | effect on the Job. |
+-------------------+--------------------+--------------------------+
| 'completed' | 'completed' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
| 'canceled' | 'canceled' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
| 'aborted' | 'aborted' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
Table 6: Release-Job State Transitions
Note 1: If there are other reasons to keep the Job in the
'pending-held' state, such as 'resources-are-not-ready', the Job
remains in the 'pending-held' state. Thus, the 'pending-held' state
is not just for Jobs that have the "job-hold-until" attribute applied
to them but is also used for any reason that will keep the Job from
being a candidate for scheduling and processing, such as
'resources-are-not-ready'. See the "job-hold-until" attribute
(Section 5.2.2).
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4.3.7. Restart-Job Operation
This DEPRECATED operation allows a Client to restart a Job that is
retained in the queue after processing has completed (see
Section 5.3.7.2).
Note: This operation SHOULD NOT be supported in new implementations,
since it destroys Printer accounting information. The Resubmit-Job
operation [PWG5100.11] is the safe replacement for this operation and
makes a copy of the Job, assigns a new "job-uri" and "job-id" to the
copy, and resets the Job progress attributes in the new copy only.
The Restart-Job operation moves the Job to the 'pending' or
'pending-held' Job state and restarts at the beginning on the same
Printer with the same attribute values. If any of the Documents in
the Job were passed by reference (Print-URI or Send-URI), the Printer
MUST refetch the data, since the semantics of Restart-Job are to
repeat all Job processing. The Job Status attributes that accumulate
Job progress, such as "job-impressions-completed",
"job-media-sheets-completed", and "job-k-octets-processed", MUST be
reset to 0 so that they give an accurate record of the Job from its
restart point. The Job MUST continue to use the same "job-uri" and
"job-id" attribute values.
The Printer MUST accept or reject the request based on the Job's
current state and transition the Job to the indicated new state as
shown in Table 7.
Note: In order to prevent a user from inadvertently restarting a Job
in the middle, the Restart-Job request is rejected when the Job is in
the 'processing' or 'processing-stopped' state. If in the future an
operation is needed to hold or restart Jobs while in either of these
states, it will be added as an additional operation, rather than
overloading the Restart-Job operation, so that it is clear that the
user intended that the current Job not be completed.
Access Rights: The authenticated user (see Section 9.3) performing
this operation must be either the Job owner or an Operator or
Administrator of the Printer (see Sections 1 and 9.5). Otherwise,
the Printer MUST reject the operation and return
'client-error-forbidden', 'client-error-not-authenticated', or
'client-error-not-authorized' as appropriate.
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+-------------------+--------------------+--------------------------+
| Current "job- | New "job-state" | Printer's response |
| state" | | status-code and action: |
+-------------------+--------------------+--------------------------+
| 'pending' | 'pending' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
| 'pending-held' | 'pending-held' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
| 'processing' | 'processing' | 'client-error-not- |
| | | possible' |
+-------------------+--------------------+--------------------------+
| 'processing- | 'processing- | 'client-error-not- |
| stopped' | stopped' | possible' |
+-------------------+--------------------+--------------------------+
| 'completed' | 'pending' or | 'successful-ok' - Job is |
| | 'pending-held' | started over. |
+-------------------+--------------------+--------------------------+
| 'completed' | 'completed' | 'client-error-not- |
| | | possible' - see Rule 1. |
+-------------------+--------------------+--------------------------+
| 'canceled' | 'pending' or | 'successful-ok' - Job is |
| | 'pending-held' | started over. |
+-------------------+--------------------+--------------------------+
| 'canceled' | 'canceled' | 'client-error-not- |
| | | possible' - see Rule 1. |
+-------------------+--------------------+--------------------------+
| 'aborted' | 'pending' or | 'successful-ok' - Job is |
| | 'pending-held' | started over. |
+-------------------+--------------------+--------------------------+
| 'aborted' | 'aborted' | 'client-error-not- |
| | | possible' - see Rule 1. |
+-------------------+--------------------+--------------------------+
Table 7: Restart-Job State Transitions
Rule 1: If the Job Retention Period has expired for the Job in this
state, then the Printer rejects the operation. See Section 5.3.7.2.
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4.3.7.1. Restart-Job Request
The groups and attributes are the same as those defined for a
Cancel-Job request (see Section 4.3.3.1), with the addition of the
following Group 1 operation attribute:
"job-hold-until" (type2 keyword | name(MAX)):
The Client MAY supply and the Printer MUST support this operation
attribute in a Restart-Job request if it supports the
"job-hold-until" Job Template attribute in Job Creation requests.
See Section 5.2.2.
If supplied and supported as specified in the Printer's
"job-hold-until-supported" attribute, the Printer copies the
supplied operation attribute to the Job, replacing the Job's
previous "job-hold-until" attribute, if present, and makes the Job
a candidate for scheduling during the supplied named time period.
See Section 5.2.2.
If supplied but the value is not supported, the Printer accepts
the request, returns the unsupported attribute or value in the
Unsupported Attributes group according to Section 4.1.7, returns
the 'successful-ok-ignored-or-substituted-attributes' status-code,
and holds the Job indefinitely until a Client performs a
subsequent Release-Job operation.
If supplied but the "job-hold-until" operation attribute itself is
not supported, the Printer accepts the request, returns the
unsupported attribute with the out-of-band 'unsupported' value in
the Unsupported Attributes group according to Section 4.1.7,
returns the 'successful-ok-ignored-or-substituted-attributes'
status-code, and restarts the Job, i.e., ignores the
"job-hold-until" attribute.
If (1) the Client supplies either a value that specifies a time
period that has already started or the 'no-hold' value (meaning
don't hold the Job) and (2) the Printer supports the
"job-hold-until" operation attribute and there are no other
reasons to hold the Job, the Printer makes the Job a candidate for
processing immediately (see Section 5.2.2).
If the Client does not supply a "job-hold-until" operation
attribute in the request, the Printer removes the "job-hold-until"
attribute, if present, from the Job. If there are no other
reasons to hold the Job, the Restart-Job operation makes the Job a
candidate for processing immediately (see Section 5.2.2).
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4.3.7.2. Restart-Job Response
The groups and attributes are the same as those defined for a
Cancel-Job response (see Section 4.3.3.2).
5. Object Attributes
This section describes the attributes with their corresponding
attribute syntaxes and values that are part of the IPP Model. The
sections below show the objects and their associated attributes that
are included within the scope of this protocol. Many of these
attributes are derived from other relevant documents:
o Document Printing Application (DPA) [ISO10175]
o Printer MIB v2 [RFC3805]
Each attribute is uniquely identified in this document using a
"keyword" (see Section 2.3.7) that is the name of the attribute. The
keyword is included in the section title describing that attribute.
Note: Not only are keywords used to identify attributes, but one of
the attribute syntaxes described below is "keyword" so that some
attributes have 'keyword' values. Therefore, these attributes are
defined as having an attribute syntax that is a set of keywords.
5.1. Attribute Syntaxes
This section defines the basic attribute syntax types that all
Clients and IPP objects MUST be able to accept in responses and
accept in requests, respectively. Each attribute description in
Sections 4 and 5 includes in the section title the name of the
attribute with its syntax(es) in parentheses. A conforming
implementation of an attribute MUST include the semantics of the
attribute syntax(es) so identified. Section 7.7 describes how the
protocol can be extended with new attribute syntaxes.
The attribute syntaxes are specified in the following subsections,
where the subsection title is the keyword name of the attribute
syntax inside the single quotes. In operation requests and
responses, each attribute value MUST be represented as one of the
attribute syntaxes specified in the subsection title for the
attribute. In addition, the value of an attribute in a response (but
not in a request) MAY be one of the "out-of-band" values
(Section 5.1.1) whose special encoding rules are defined in the
Encoding and Transport document [RFC8010].
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All attributes in a request MUST have one or more values as defined
in Sections 5.2, 5.3, and 5.4. All attributes in a response MUST
have either (1) one or more values as defined in Sections 5.2, 5.3,
and 5.4 or (2) a single "out-of-band" value.
Most attributes are defined to have a single attribute syntax.
However, a few attributes (e.g., "job-sheet", "media",
"job-hold-until") are defined to have several attribute syntaxes,
depending on the value. These multiple attribute syntaxes are
separated by the "|" character in the subsection title to indicate
the choice. Since each value MUST be tagged as to its attribute
syntax in the protocol, a single-valued attribute instance can have
any one of its attribute syntaxes and a multi-valued attribute
instance can have a mixture of its defined attribute syntaxes.
5.1.1. Out-of-Band Values - 'unknown', 'unsupported', and 'no-value'
This document defines three "out-of-band" values that are used in
place of an attribute's defined syntax:
o 'unknown': The attribute is supported by the IPP object, but the
value is unknown to the IPP object for some reason. This
out-of-band value is used for attributes that have an intrinsic,
physical value that cannot be determined by the IPP object at a
given time, e.g., sheet count, geo-location, etc.
o 'unsupported': The attribute is unsupported by the IPP object.
This value MUST be returned only as the value of an attribute in
the Unsupported Attributes group.
o 'no-value': The attribute is supported by the Printer, but the
Administrator has not yet configured a value.
5.1.2. 'text'
A 'text' attribute is an attribute whose value is a sequence of zero
or more characters encoded in a maximum of 1023 ('MAX') octets. MAX
is the maximum length for each value of any 'text' attribute.
However, if an attribute will always contain values whose maximum
length is much less than MAX, the definition of that attribute will
include a qualifier that defines the maximum length for values of
that attribute. For example, the "printer-location" attribute is
specified as "printer-location (text(127))". In this case, text
values for "printer-location" MUST NOT exceed 127 octets; if supplied
with a longer text string via some external interface (other than the
protocol), implementations are free to truncate to this shorter
length limitation.
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In this document, all 'text' attributes are defined using the 'text'
syntax. However, 'text' is used only for brevity; the formal
interpretation of 'text' is 'textWithoutLanguage | textWithLanguage'.
That is, for any attribute defined in this document using the 'text'
attribute syntax, all IPP objects and Clients MUST support both the
'textWithoutLanguage' and 'textWithLanguage' attribute syntaxes.
However, in actual usage and protocol execution, IPP objects and
Clients accept and return only one of the two syntaxes per attribute.
The syntax 'text' never appears "on-the-wire".
Both 'textWithoutLanguage' and 'textWithLanguage' are needed to
support the real-world needs of interoperability between sites and
systems that use different natural languages as the basis for human
communication. Generally, one natural language applies to all 'text'
attributes in a given request or response. The language is indicated
by the "attributes-natural-language" operation attribute defined in
Section 4.1.4 or the "attributes-natural-language" Job attribute
defined in Section 5.3.20, and there is no need to identify the
natural language for each text string on a value-by-value basis. In
these cases, the attribute syntax 'textWithoutLanguage' is used for
'text' attributes. In other cases, the Client needs to supply or the
Printer needs to return a text value in a natural language that is
different from the rest of the text values in the request or
response. In these cases, the Client or Printer uses the attribute
syntax 'textWithLanguage' for 'text' attributes (this is the Natural
Language Override mechanism described in Section 4.1.4).
The 'textWithoutLanguage' and 'textWithLanguage' attribute syntaxes
are described in more detail in the following sections.
5.1.2.1. 'textWithoutLanguage'
The 'textWithoutLanguage' syntax indicates a value that is a sequence
of zero or more characters encoded in a maximum of 1023 (MAX) octets.
Text strings are encoded using the rules of some charset. The
Printer MUST support the UTF-8 charset [RFC3629] and MAY support
additional charsets to represent 'text' values, provided that the
charsets are registered with IANA [IANA-CS]. See Section 5.1.8 for
the definition of the 'charset' attribute syntax, including
restricted semantics and examples of charsets.
5.1.2.2. 'textWithLanguage'
The 'textWithLanguage' attribute syntax is a compound attribute
syntax consisting of two parts: a 'textWithoutLanguage' part encoded
in a maximum of 1023 (MAX) octets plus an additional
'naturalLanguage' (see Section 5.1.9) part that overrides the natural
language in force. The 'naturalLanguage' part explicitly identifies
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the natural language that applies to the text part of that value and
that value alone. For any given 'text' attribute, the
'textWithoutLanguage' part is limited to the maximum length defined
for that 'text' attribute, and the 'naturalLanguage' part is always
limited to 63 (additional) octets. Using the 'textWithLanguage'
attribute syntax rather than the normal 'textWithoutLanguage' syntax
is the so-called "Natural Language Override mechanism" and MUST be
supported by all IPP objects and Clients.
If the attribute is multi-valued (1setOf text), then the
'textWithLanguage' attribute syntax MUST be used to explicitly
specify each attribute value whose natural language needs to be
overridden. Other values in a multi-valued 'text' attribute in a
request or a response revert to the natural language of the operation
attribute.
In a Job Creation request, the Printer MUST accept and store with the
Job any natural language in the "attributes-natural-language"
operation attribute, whether the Printer supports that natural
language or not. Furthermore, the Printer MUST accept and store any
'textWithLanguage' attribute value, whether the Printer supports that
natural language or not. These requirements are independent of the
value of the "ipp-attribute-fidelity" operation attribute that the
Client MAY supply.
Example: If the Client supplies the "attributes-natural-language"
operation attribute with the value 'en' indicating English but the
value of the "job-name" attribute is in French, the Client MUST use
the 'textWithLanguage' attribute syntax with the following two
values:
'fr': Natural Language Override indicating French
'Rapport Mensuel': the Job name in French
See the Encoding and Transport document [RFC8010] for the encoding of
the two parts and a detailed example of the 'textWithLanguage'
attribute syntax.
5.1.3. 'name'
This syntax type is used for user-friendly strings, such as a Printer
name, that, for humans, are more meaningful than identifiers. Names
are never translated from one natural language to another. The
'name' attribute syntax is essentially the same as 'text', including
the REQUIRED support of UTF-8, except that the sequence of characters
is limited so that its encoded form MUST NOT exceed 255 (MAX) octets.
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Also, like 'text', 'name' is really an abbreviated notation for
either 'nameWithoutLanguage' or 'nameWithLanguage'. That is, all IPP
objects and Clients MUST support both the 'nameWithoutLanguage' and
'nameWithLanguage' attribute syntaxes. However, in actual usage and
protocol execution, IPP objects and Clients accept and return only
one of the two syntaxes per attribute. The syntax 'name' never
appears "on-the-wire".
Only the 'text' and 'name' attribute syntaxes permit the Natural
Language Override mechanism.
Some attributes are defined as 'type2 keyword | name'. These
attributes support values that are either type2 keywords or names.
This dual-syntax mechanism enables a site Administrator to extend
these attributes to legally include values that are locally defined
by the site Administrator. Such names are not registered with IANA.
5.1.3.1. 'nameWithoutLanguage'
The 'nameWithoutLanguage' syntax indicates a value that is a sequence
of zero or more characters encoded in a maximum of 255 (MAX) octets.
5.1.3.2. 'nameWithLanguage'
The 'nameWithLanguage' attribute syntax is a compound attribute
syntax consisting of two parts: a 'nameWithoutLanguage' (see
Section 5.1.3.1) part plus an additional 'naturalLanguage' (see
Section 5.1.9) part that overrides the natural language in force.
The 'naturalLanguage' part explicitly identifies the natural language
that applies to that name value and that name value alone. For any
given 'name' attribute, the 'nameWithoutLanguage' part is limited to
the maximum length defined for that 'name' attribute, and the
'naturalLanguage' part is always limited to 63 (additional) octets.
Using the 'nameWithLanguage' attribute syntax rather than the normal
'nameWithoutLanguage' syntax is the Natural Language Override
mechanism and MUST be supported by all IPP objects and Clients.
The 'nameWithLanguage' attribute syntax behaves the same as the
'textWithLanguage' syntax. If a name is in a language that is
different than the rest of the object or operation, then this
'nameWithLanguage' syntax is used rather than the generic
'nameWithoutLanguage' syntax.
If the attribute is multi-valued (1setOf name), then the
'nameWithLanguage' attribute syntax MUST be used to explicitly
specify each attribute value whose natural language needs to be
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overridden. Other values in a multi-valued 'name' attribute in a
request or a response revert to the natural language of the operation
attribute.
In a Job Creation request, the Printer MUST accept and store with the
Job any natural language in the "attributes-natural-language"
operation attribute, whether the Printer supports that natural
language or not. Furthermore, the Printer MUST accept and store any
'nameWithLanguage' attribute value, whether the Printer supports that
natural language or not. These requirements are independent of the
value of the "ipp-attribute-fidelity" operation attribute that the
Client MAY supply.
Example: If the Client supplies the "attributes-natural-language"
operation attribute with the value 'en' indicating English but the
"printer-name" attribute is in German, the Client MUST use the
'nameWithLanguage' attribute syntax as follows:
'de': Natural Language Override indicating German
'Farbdrucker': the Printer name in German
See the Encoding and Transport document [RFC8010] for the encoding of
the two parts and a detailed example of the 'nameWithLanguage'
attribute syntax.
5.1.3.3. Matching 'name' Attribute Values
For purposes of matching two 'name' attribute values for equality,
such as in Job validation (where a Client-supplied value for
attribute "xxx" is checked to see if the value is among the values of
the Printer's corresponding "xxx-supported" attribute), the following
match rules apply:
1. 'keyword' values never match 'name' values.
2. 'name' ('nameWithoutLanguage' and 'nameWithLanguage') values
match if (1) the name parts match and (2) the Associated
Natural Language parts (see Section 4.1.4.1) match. The matching
rules are as follows:
2a. The name parts match if the two names are identical
character by character, except that it is RECOMMENDED that
case be ignored as defined in "i;unicode-casemap - Simple
Unicode Collation Algorithm" [RFC5051]. For example,
'Ajax-letter-head-white' MUST match 'Ajax-letter-head-white'
and SHOULD match 'ajax-letter-head-white' and
'AJAX-LETTER-HEAD-WHITE'.
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2b. The Associated Natural Language parts match if the shorter
of the two meets the syntactic requirements defined in
Section 2.1 of RFC 5646 [RFC5646] and matches (byte for
byte, since IPP language tags are lowercase) with the
longer. For example, 'en' matches 'en', 'en-us', and
'en-gb' but matches neither 'fr' nor 'e'.
5.1.4. 'keyword'
The 'keyword' attribute syntax is a sequence of characters, of length
1 to 255, containing only the US-ASCII [RFC20] encoded values for
lowercase letters ("a"-"z"), digits ("0"-"9"), hyphen ("-"), dot
("."), and underscore ("_"). The first character MUST be a lowercase
letter. Furthermore, keywords MUST be in US English.
This syntax type is used for enumerating semantic identifiers of
entities in the abstract protocol, i.e., entities identified in this
document. Keywords are used as attribute names or values of
attributes. Unlike 'text' and 'name' attribute values, 'keyword'
values MUST NOT use the Natural Language Override mechanism, since
they MUST always be US-ASCII and US English.
Keywords are for use in the protocol. A user interface will likely
provide a mapping between protocol keywords and displayable
user-friendly words and phrases that are localized to the natural
language of the user. While the keywords specified in this document
MAY be displayed to users whose natural language is US English, they
MAY be mapped to other US English words for US English users, since
the user interface is outside the scope of this document.
In the definition for each attribute of this syntax type, the full
set of 'keyword' values being defined for that attribute is listed.
The IANA IPP registry will always contain the complete and current
list of 'keyword' values for the attribute.
When a keyword is used to represent an attribute (its name), it MUST
be unique within the full scope of all IPP objects and attributes.
When a keyword is used to represent a value of an attribute, it MUST
be unique just within the scope of that attribute. That is, the same
keyword MUST NOT be used for two different values within the same
attribute to mean two different semantic ideas. However, the same
keyword MAY be used across two or more attributes, representing
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different semantic ideas for each attribute. Section 7.3 describes
how the protocol can be extended with new 'keyword' values. Examples
of attribute name keywords are:
"job-name"
"attributes-charset"
Note: This document uses "type1" and "type2" prefixes to the
"keyword" basic syntax to indicate different levels of review for
extensions (see Section 7.3).
5.1.5. 'enum'
The 'enum' attribute syntax is an enumerated integer value that is in
the range from 1 to 2**31 - 1 (MAX). Each value has an associated
'keyword' name. In the definition for each attribute of this syntax
type, the full set of possible values for that attribute is listed.
This syntax type is used for attributes for which there are enum
values assigned by other standards, such as SNMP MIBs. A number of
attribute enum values in this document are also used for
corresponding attributes in other standards [RFC3805]. This syntax
type is not used for attributes to which the Administrator can assign
values. Section 7.4 describes how the protocol can be extended with
new enum values.
Enum values are for use in the protocol. A user interface will
provide a mapping between protocol enum values and displayable
user-friendly words and phrases that are localized to the natural
language of the user. While the enum symbols specified in this
document MAY be displayed to users whose natural language is
US English, they MAY be mapped to other US English words for
US English users, since the user interface is outside the scope of
this document.
Note: Some SNMP MIBs use '2' for 'unknown', which corresponds to the
IPP "out-of-band" value 'unknown'. See the description of the
"out-of-band" values at the beginning of Section 5.1. Therefore,
attributes of type 'enum' typically start at '3'.
Note: This document uses "type1" and "type2" prefixes to the "enum"
basic syntax to indicate different levels of review for extensions
(see Section 7.4).
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5.1.6. 'uri'
The 'uri' attribute syntax is any valid Uniform Resource Identifier
(URI) [RFC3986]. Most often, URIs are simply Uniform Resource
Locators (URLs). The maximum length of URIs used as values of IPP
attributes is 1023 octets. Although most other IPP attribute syntax
types allow for only lowercase values, this attribute syntax type
conforms to the case-sensitive and case-insensitive rules specified
in [RFC3986]. See also [RFC3196] for a discussion of case in URIs.
5.1.7. 'uriScheme'
The 'uriScheme' attribute syntax is a sequence of characters
representing a URI scheme according to RFC 3986 [RFC3986]. Though
RFC 3986 requires that the values be case insensitive, IPP requires
all lowercase values in IPP attributes, to simplify comparing by IPP
Clients and Printers.
Standard values for this syntax type include the following keywords:
o 'ipp': for IPP schemed URIs, e.g., "ipp://example.com/ipp/..."
[RFC3510]
o 'ipps': for IPPS schemed URIs, e.g., "ipps://example.com/ipp/..."
[RFC7472]
o 'http': for HTTP schemed URIs, e.g., "http://example.com/path/to/
filename" [RFC7230]
o 'https': for HTTPS schemed URIs, e.g.,
"https://example.com/path/to/filename" [RFC7230]
o 'ftp': for FTP schemed URIs, e.g., "ftp://example.com/path/to/
filename" [RFC1738]
o 'mailto': for SMTP schemed URIs, e.g., "mailto:user@example.com"
[RFC6068]
o 'file': for file schemed URIs, e.g., "file:///path/to/filename"
[RFC1738]
o 'urn': for Uniform Resource Name schemed URIs, e.g.,
"urn:uuid:01234567-89ab-cdef-fedc-ba9876543210" [RFC4122]
A Printer MAY support any URI 'scheme' that has been registered with
IANA [IANA-MT]. The maximum length of URI 'scheme' values used to
represent IPP attribute values is 63 octets.
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5.1.8. 'charset'
The 'charset' attribute syntax is a standard identifier for a
charset. A charset is a coded character set and encoding scheme.
Charsets are used for labeling certain Document contents, 'text'
attribute values, and 'name' attribute values. The syntax and
semantics of this attribute syntax are specified in RFC 2046
[RFC2046] and contained in the IANA "Character Sets" registry
[IANA-CS] according to the IANA procedures [RFC2978]. Though
RFC 2046 requires that the values be case-insensitive US-ASCII
[RFC20], IPP requires all lowercase values in IPP attributes, to
simplify comparing by IPP Clients and Printers. When a character set
in the IANA registry has more than one name (alias), the name labeled
as "(preferred MIME name)", if present, MUST be used.
The maximum length of 'charset' values used to represent IPP
attribute values is 63 octets.
Some examples are:
o 'utf-8': ISO 10646 Universal Multiple-Octet Coded Character Set
(UCS) [ISO10646] represented as the UTF-8 [RFC3629] transfer
encoding scheme in which US-ASCII [RFC20] is a subset charset.
o 'us-ascii': 7-bit American Standard Code for Information
Interchange (ASCII) [RFC20].
o 'iso-8859-1': 8-bit One-Byte Coded Character Set, Latin Alphabet
No. 1 [ISO8859-1]. That standard defines a coded character set
that is used by Latin languages in the Western Hemisphere and
Western Europe. US-ASCII is a subset charset.
Some attribute descriptions MAY place additional requirements on
charset values that can be used, such as REQUIRED values that MUST be
supported or additional restrictions, such as requiring that the
charset have US-ASCII as a subset charset.
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5.1.9. 'naturalLanguage'
The 'naturalLanguage' attribute syntax is a standard identifier for a
natural language and, optionally, a country or region. The values
for this syntax type are defined by RFC 5646 [RFC5646]. Though
RFC 5646 requires that the values be case-insensitive US-ASCII, IPP
requires all lowercase values in IPP attributes, to simplify
comparing by IPP Clients and Printers. Examples include:
o 'en': for English
o 'en-us': for US English
o 'fr': for French
o 'de': for German
The maximum length of 'naturalLanguage' values used to represent IPP
attribute values is 63 octets.
Note: While any standard natural language identifier defined in
RFC 5646 can be used, Clients typically only support a subset of
these identifiers. When comparing two identifiers or performing
lookups, Printers SHOULD be prepared to match legacy identifiers with
their corresponding modern equivalents and vice versa.
5.1.10. 'mimeMediaType'
The 'mimeMediaType' attribute syntax is the Internet media type
(sometimes called "MIME type") as defined by RFC 2046 [RFC2046] and
registered according to the procedures of RFC 6838 [RFC6838] for
identifying a Document format. The value MAY include a charset
parameter, or some other parameter, depending on the specification of
the media type in the IANA "Media Types" registry [IANA-MT].
Although most other IPP syntax types allow for only lowercase values,
this syntax type allows for mixed-case values that are
case insensitive.
Examples are:
o 'text/html': An HTML Document
o 'text/plain': A plain text Document in US-ASCII (RFC 2046
indicates that in the absence of the charset parameter MUST mean
US-ASCII rather than simply unspecified) [RFC2046]
o 'text/plain; charset = US-ASCII': A plain text Document in
US-ASCII
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o 'text/plain; charset = ISO-8859-1': A plain text Document in
ISO 8859-1 (Latin 1) [ISO8859-1]
o 'text/plain; charset = utf-8': A plain text Document in ISO 10646
represented as UTF-8 [RFC3629]
o 'application/postscript': A PostScript Document [RFC2046]
o 'application/vnd.hp-PCL': A PCL Document [IANA-MT] (charset escape
sequence embedded in the Document data)
o 'application/pdf': Portable Document Format [ISO32000]
o 'application/octet-stream': Auto-sense - see Section 5.1.10.1
The maximum length of a 'mimeMediaType' value to represent IPP
attribute values is 255 octets.
5.1.10.1. 'application/octet-stream' - Auto-Sensing the Document Format
One special type is 'application/octet-stream'. If the Printer
supports this value, the Printer MUST be capable of auto-sensing the
format of the Document data using an implementation-dependent method
that examines some number of octets of the Document data, either as
part of the Job Creation request and/or at Document processing time.
During auto-sensing, a Printer can determine that the Document data
has a format that the Printer doesn't recognize. If the Printer
determines this problem before returning an operation response, it
rejects the request and returns the
'client-error-document-format-not-supported' status-code. If the
Printer determines this problem after accepting the request and
returning an operation response with one of the successful
status-code values, the Printer adds the
'unsupported-document-format' value to the Job's "job-state-reasons"
attribute.
If the Printer's default value attribute "document-format-default" is
set to 'application/octet-stream', the Printer not only supports
auto-sensing of the Document format but will depend on the result of
applying its auto-sensing when the Client does not supply the
"document-format" attribute. If the Client supplies a Document
format value, the Printer MUST rely on the supplied attribute, rather
than trust its auto-sensing algorithm. To summarize:
1. If the Client does not supply a Document format value, the
Printer MUST rely on its default value setting (which can be
'application/octet-stream' indicating an auto-sensing mechanism).
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2. If the Client supplies a value other than
'application/octet-stream', the Client is supplying valid
information about the format of the Document data and the Printer
MUST trust the Client-supplied value more than the outcome of
applying an automatic format detection mechanism. For example,
the Client can request the printing of a PostScript file as a
'text/plain' Document. The Printer MUST print a text
representation of the PostScript commands rather than interpret
the stream of PostScript commands and print the result.
3. If the Client supplies a value of 'application/octet-stream', the
Client is indicating that the Printer MUST use its auto-sensing
mechanism on the Client-supplied Document data whether
auto-sensing is the Printer's default or not.
Note: Since the auto-sensing algorithm is probabilistic, if the
Client requests both auto-sensing ("document-format" set to
'application/octet-stream') and true fidelity
("ipp-attribute-fidelity" set to 'true'), the Printer might not be
able to guarantee exactly what the End User intended (the
auto-sensing algorithm might mistake one Document format for
another), but it is able to guarantee that its auto-sensing mechanism
will be used.
5.1.11. 'octetString'
The 'octetString' attribute syntax is a sequence of octets encoded in
a maximum of 1023 octets that is indicated in syntax definitions
using the notation 'octetString(MAX)'. This syntax type is used for
opaque data.
5.1.12. 'boolean'
The 'boolean' attribute syntax has only two values: 'true' and
'false'.
5.1.13. 'integer'
The 'integer' attribute syntax is an integer value that is in the
range from -2**31 (MIN) to 2**31 - 1 (MAX). Each individual
attribute can specify the range constraint explicitly if the range is
different from the full range of possible integer values -- for
example, job-priority (integer(1:100)) for the "job-priority"
attribute, as shown in the title of Section 5.2.1. However, the
enforcement of that additional constraint is up to the IPP objects,
not the protocol.
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5.1.14. 'rangeOfInteger'
The 'rangeOfInteger' attribute syntax is an ordered pair of integers
that defines an inclusive range of integer values. The first integer
specifies the lower bound, and the second specifies the upper bound.
If a range constraint is specified in the attribute definition, i.e.,
'rangeOfInteger(X:Y)' indicating X as a minimum value and Y as a
maximum value, then the constraint applies to both integers.
5.1.15. 'dateTime'
The 'dateTime' attribute syntax is a standard, fixed-length, 11-octet
representation of the "DateAndTime" syntax as defined in RFC 2579
[RFC2579]. RFC 2579 also identifies an 8-octet representation of a
"DateAndTime" value, but IPP objects MUST use the 11-octet
representation. A user interface will provide a mapping between
protocol dateTime values and displayable user-friendly words or
presentation values and phrases that are localized to the natural
language and date format of the user, including time zone.
5.1.16. 'resolution'
The 'resolution' attribute syntax specifies a two-dimensional
resolution in the indicated units. It consists of three values: a
cross-feed direction resolution (positive integer value), a feed
direction resolution (positive integer value), and a units value.
The semantics of these three components are taken from the suggested
values in the Printer MIB [RFC3805]. That is, the cross-feed
direction resolution component is the same as the
prtMarkerAddressabilityXFeedDir object in the Printer MIB, the feed
direction resolution component is the same as the
prtMarkerAddressabilityFeedDir in the Printer MIB, and the units
component is the same as the prtMarkerAddressabilityUnit object in
the Printer MIB (namely, '3' indicates dots per inch and '4'
indicates dots per centimeter). All three values MUST be present
even if the first two values are the same. For example, '300',
'600', '3' indicates a 300-dpi cross-feed direction resolution and a
600-dpi feed direction resolution, since a '3' indicates dots per
inch (dpi).
5.1.17. 'collection'
The 'collection' attribute syntax is a container holding one or more
named values (i.e., attributes), which are called "member
attributes". Each 'collection' attribute definition Document lists
the mandatory and optional member attributes of each collection
value. A collection value is similar to an IPP attribute group in a
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request or a response, such as the Operation Attributes group -- they
both consist of a set of attributes. Collections can also be nested,
i.e., a collection in a collection.
A collection value consists of three separate components:
o A 'begCollection' value with an optional octet string value
starting the collection,
o Zero or more member attributes defined using a series of unnamed
values starting with a 'memberAttrName' value that specifies the
member attribute name, and
o An 'endCollection' value with an optional name plus octet string
value finishing the collection.
5.1.18. '1setOf X'
The '1setOf X' attribute syntax is one or more values of attribute
syntax type X. This syntax type is used for multi-valued attributes.
The syntax type is called '1setOf' rather than just 'setOf' as a
reminder that the set of values MUST NOT be empty (i.e., a set of
size 0). Sets are normally unordered; however, each attribute
description of this type can specify that the values MUST be in a
certain order for that attribute.
5.2. Job Template Attributes
Job Template attributes describe Job processing intent. Clients MAY
supply (in Job Creation requests) and Printers SHOULD support Job
Template attributes. See Section 2.3.11 for a description of support
for OPTIONAL attributes.
Job Template attributes conform to the following rules. For each Job
Template attribute called "xxx":
1. If the Printer supports "xxx", then it MUST support both an
"xxx-default" attribute (unless there is a "No" in Table 8 below)
and an "xxx-supported" attribute. If the Printer doesn't support
"xxx", then it MUST support neither an "xxx-default" attribute
nor an "xxx-supported" attribute, and it MUST treat an attribute
"xxx" supplied by a Client as unsupported. An attribute "xxx"
can be supported for some Document formats and not supported for
other Document formats. For example, it is expected that a
Printer would only support "orientation-requested" for some
Document formats (such as 'text/plain' or 'text/html') but not
others (such as 'application/postscript').
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2. Clients MAY supply "xxx" in a Job Creation request. If "xxx" is
supplied, the Client is indicating a desired Job processing
behavior for this Job. When "xxx" is not supplied, the Client is
indicating that the Printer apply its default Job processing
behavior at Job processing time if the Document content does not
contain an embedded instruction indicating an xxx-related
behavior.
Since an Administrator MAY change the default value attribute
after a Job has been submitted but before it has been processed,
the default value used by the Printer at Job processing time can
be different than the default value in effect at Job submission
time.
3. The "xxx-supported" attribute is a Printer attribute that
describes which Job processing behaviors are supported by that
Printer. A Client can query the Printer to find out what
xxx-related behaviors are supported by inspecting the returned
values of the "xxx-supported" attribute.
Note: The "xxx" in each "xxx-supported" attribute name is
singular, even though an "xxx-supported" attribute usually has
more than one value, such as "print-quality-supported", unless
the "xxx" Job Template attribute is plural, such as "finishings"
or "sides". In such cases, the "xxx-supported" attribute names
are "finishings-supported" and "sides-supported".
4. The "xxx-default" default value attribute describes what will be
done at Job processing time when no other Job processing
information is supplied by the Client (either explicitly as an
IPP attribute in the Job Creation request or implicitly as an
embedded instruction within the Document data).
If an application wishes to present an End User with a list of
supported values from which to choose, the application SHOULD query
the Printer for its supported value attributes. The application
SHOULD also query the default value attributes. If the application
then limits selectable values to only those values that are
supported, the application can guarantee that the values supplied by
the Client in the Job Creation request all fall within the set of
supported values at the Printer. When querying the Printer, the
Client MAY enumerate each attribute by name in the
Get-Printer-Attributes request, or the Client MAY just name the
"job-template" group in order to get the complete set of supported
attributes (both supported and default attributes).
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The "finishings" attribute is an example of a Job Template attribute.
It can take on a set of values such as '4' ('staple'), '5' ('punch'),
and/or '6' ('cover'); see Table 10 in Section 5.2.6. A Client can
query the Printer for the "finishings-supported" attribute and the
"finishings-default" attribute. The supported attribute contains a
set of supported values. The default value attribute contains the
finishing value(s) that will be used for a new Job if the Client does
not supply a "finishings" attribute in the Job Creation request and
the Document data does not contain any corresponding finishing
instructions. If the Client does supply the "finishings" attribute
in the Job Creation request, the Printer validates the value or
values to make sure that they are a subset of the supported values
identified in the Printer's "finishings-supported" attribute. See
Section 4.1.7.
Table 8 below summarizes the names and relationships for all Job
Template attributes. The first column of the table (labeled "Job
Attribute") shows the name and syntax for each Job Template attribute
in the Job. These are the attributes that can optionally be supplied
by the Client in a Job Creation request. The last two columns
(labeled "Printer: Default Value Attribute" and "Printer: "Supported
Values" Attribute") show the name and syntax for each Job Template
attribute in the Printer (the default value attributes and the
"supported values" attributes). A "No" in the table means the
Printer MUST NOT support the attribute (that is, the attribute is
simply not applicable). For brevity in the table, the 'text' and
'name' entries do not show the maximum length for each attribute.
+------------------+----------------------+-------------------------+
| Job Attribute | Printer: Default | Printer: "Supported |
| | Value Attribute | Values" Attribute |
+------------------+----------------------+-------------------------+
| job-priority | job-priority-default | job-priority-supported |
| (integer 1:100) | (integer 1:100) | (integer 1:100) |
+------------------+----------------------+-------------------------+
| job-hold-until | job-hold-until- | job-hold-until- |
| (type2 keyword | | default (type2 | supported (1setOf |
| name) | keyword | name) | (type2 keyword | name)) |
+------------------+----------------------+-------------------------+
| job-sheets | job-sheets-default | job-sheets-supported |
| (type2 keyword | | (type2 keyword | | (1setOf (type2 keyword |
| name) | name) | | name)) |
+------------------+----------------------+-------------------------+
| multiple- | multiple-document- | multiple-document- |
| document- | handling-default | handling-supported |
| handling (type2 | (type2 keyword) | (1setOf type2 keyword) |
| keyword) | | |
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+------------------+----------------------+-------------------------+
| copies | copies-default | copies-supported |
| (integer(1:MAX)) | (integer(1:MAX)) | (rangeOfInteger(1:MAX)) |
+------------------+----------------------+-------------------------+
| finishings | finishings-default | finishings-supported |
| (1setOf type2 | (1setOf type2 enum) | (1setOf type2 enum) |
| enum) | | |
+------------------+----------------------+-------------------------+
| page-ranges | No | page-ranges-supported |
| (1setOf | | (boolean) |
| rangeOfInteger | | |
| (1:MAX)) | | |
+------------------+----------------------+-------------------------+
| sides (type2 | sides-default (type2 | sides-supported (1setOf |
| keyword) | keyword) | type2 keyword) |
+------------------+----------------------+-------------------------+
| number-up | number-up-default | number-up-supported |
| (integer(1:MAX)) | (integer(1:MAX)) | (1setOf |
| | | (integer(1:MAX) | |
| | | rangeOfInteger(1:MAX))) |
+------------------+----------------------+-------------------------+
| orientation- | orientation- | orientation-requested- |
| requested (type2 | requested-default | supported (1setOf type2 |
| enum) | (type2 enum) | enum) |
+------------------+----------------------+-------------------------+
| media (type2 | media-default (type2 | media-supported (1setOf |
| keyword | name) | keyword | name) | (type2 keyword | name)) |
| | | media-ready (1setOf |
| | | (type2 keyword | name)) |
+------------------+----------------------+-------------------------+
| printer- | printer-resolution- | printer-resolution- |
| resolution | default (resolution) | supported (1setOf |
| (resolution) | | resolution) |
+------------------+----------------------+-------------------------+
| print-quality | print-quality- | print-quality-supported |
| (type2 enum) | default (type2 enum) | (1setOf type2 enum) |
+------------------+----------------------+-------------------------+
Table 8: Job Template Attributes
5.2.1. job-priority (integer(1:100))
This attribute specifies a priority for scheduling the Job. A higher
value specifies a higher priority. The value 1 indicates the lowest
possible priority. The value 100 indicates the highest possible
priority. Among those Jobs that are ready to print, a Printer MUST
print all Jobs with a priority value of n before printing those with
a priority value of n - 1 for all n.
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If the Printer supports this attribute, it MUST always support the
full range from 1 to 100. No administrative restrictions are
permitted. This way, an End User can always make full use of the
entire range with any Printer. If privileged Jobs are implemented
outside IPP, they MUST have priorities higher than 100, rather than
restricting the range available to End Users.
If the Client does not supply this attribute and this attribute is
supported by the Printer, the Printer MUST use the value of the
Printer's "job-priority-default" attribute at Job submission time
(unlike most Job Template attributes that are used if necessary at
Job processing time).
The syntax for the "job-priority-supported" attribute is also
integer(1:100). This single integer value indicates the number of
priority levels supported. The Printer MUST take the value supplied
by the Client and map it to the closest integer in a sequence of
n integer values that are evenly distributed over the range from
1 to 100 using the formula:
roundToNearestInt((100x + 50) / n)
where n is the value of "job-priority-supported" and x ranges from
0 through (n - 1).
For example, if n = 1, the sequence of values is 50; if n = 2, the
sequence of values is 25 and 75; if n = 3, the sequence of values is
17, 50, and 83; if n = 10, the sequence of values is 5, 15, 25, 35,
45, 55, 65, 75, 85, and 95; if n = 100, the sequence of values is
1, 2, 3, ... 100.
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Table 9 shows how a Printer maps Client-supplied "job-priority"
values for example values of n.
+--------------+-------+-------+--------+
| job-priority | n = 1 | n = 2 | n = 10 |
+--------------+-------+-------+--------+
| 1 | 50 | 17 | 5 |
+--------------+-------+-------+--------+
| 10 | 50 | 17 | 5 |
+--------------+-------+-------+--------+
| 20 | 50 | 17 | 15 |
+--------------+-------+-------+--------+
| 30 | 50 | 17 | 25 |
+--------------+-------+-------+--------+
| 40 | 50 | 50 | 35 |
+--------------+-------+-------+--------+
| 50 | 50 | 50 | 45 |
+--------------+-------+-------+--------+
| 60 | 50 | 50 | 55 |
+--------------+-------+-------+--------+
| 70 | 50 | 50 | 65 |
+--------------+-------+-------+--------+
| 80 | 50 | 83 | 75 |
+--------------+-------+-------+--------+
| 90 | 50 | 83 | 85 |
+--------------+-------+-------+--------+
| 100 | 50 | 83 | 95 |
+--------------+-------+-------+--------+
Table 9: "job-priority" Values
5.2.2. job-hold-until (type2 keyword | name(MAX))
This attribute specifies the named time period during which the Job
MUST become a candidate for printing.
Standard 'keyword' values for named time periods are:
o 'no-hold': immediately, if there are no other reasons to hold
the job
o 'indefinite': the Job is held indefinitely, until a Client
performs a Release-Job (Section 4.3.6)
o 'day-time': during the day
o 'evening': evening
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o 'night': night
o 'weekend': weekend
o 'second-shift': second shift (after close of business)
o 'third-shift': third shift (after midnight)
An Administrator MUST associate allowable print times with a named
time period (by means outside the scope of this IPP/1.1 document).
An Administrator is encouraged to pick names that suggest the type of
time period. An Administrator MAY define additional values using the
'name' or 'keyword' attribute syntax, depending on implementation.
If the value of this attribute specifies a time period that is in the
future, the Printer SHOULD add the "job-hold-until-specified" value
to the Job's "job-state-reasons" attribute, MUST move the Job to the
'pending-held' state, and MUST NOT schedule the Job for printing
until the specified time period arrives.
When the specified time period arrives, the Printer MUST remove the
"job-hold-until-specified" value from the Job's "job-state-reasons"
attribute, if present. If there are no other Job state reasons that
keep the Job in the 'pending-held' state, the Printer MUST consider
the Job as a candidate for processing by moving the Job to the
'pending' state.
If this Job attribute value is the named value 'no-hold' or the
specified time period has already started, the Job MUST be a
candidate for processing immediately.
If the Client does not supply this attribute and this attribute is
supported by the Printer, the Printer MUST use the value of the
Printer's "job-hold-until-default" at Job submission time (unlike
most Job Template attributes that are used if necessary at Job
processing time).
5.2.3. job-sheets (type2 keyword | name(MAX))
This attribute determines which Job start/end sheet(s), if any, MUST
be printed with a Job.
Standard 'keyword' values are:
o 'none': no Job sheet is printed
o 'standard': one or more site-specific standard Job sheets are
printed, e.g., a single start sheet or both start and end sheets
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An Administrator MAY define additional values using the 'name' or
'keyword' attribute syntax, depending on implementation.
The effect of this attribute on Jobs with multiple Documents MAY be
affected by the "multiple-document-handling" Job attribute
(Section 5.2.4), depending on the Job sheet semantics.
5.2.4. multiple-document-handling (type2 keyword)
This RECOMMENDED attribute controls which Impressions and Media
Sheets constitute a Set for copy generation and finishing processes.
When the value of the "copies" attribute exceeds '1', it also
controls the order in which the copies that result from processing
the Documents are produced. For the purposes of this explanation, if
"a" represents an instance of Document data, then the result of
processing the data in Document "a" is a sequence of Media Sheets
represented by "a(*)". This attribute MUST be supported with at
least one value if the Printer supports multiple Documents per Job
(see Sections 4.2.4 and 4.3.1).
Standard 'keyword' values are:
o 'single-document': If a Job has multiple Documents, say, the
Document data is called "a" and "b", then the result of processing
all the Document data (a and then b) MUST be treated as a single
sequence of Media Sheets for finishing processes; that is,
finishing is performed on the concatenation of the sequences
a(*),b(*). The Printer MUST NOT force the data in each Document
instance to be formatted onto a new Impression, nor to start a new
Impression on a new Media Sheet. If more than one copy is made,
the ordering of the sets of Media Sheets resulting from processing
the Document data MUST be a(*), b(*), a(*), b(*), ..., and the
Printer MUST force each copy (a(*),b(*)) to start on a new Media
Sheet.
o 'separate-documents-uncollated-copies': If a Job has multiple
Documents, say, the Document data is called "a" and "b", then the
result of processing the data in each Document instance MUST be
treated as a single sequence of Media Sheets for finishing
processes; that is, the sets a(*) and b(*) would each be finished
separately. The Printer MUST force each copy of the result of
processing the data in a single Document to start on a new Media
Sheet. If more than one copy is made, the ordering of the sets of
Media Sheets resulting from processing the Document data MUST be
a(*), a(*), ..., b(*), b(*), ... .
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o 'separate-documents-collated-copies': If a Job has multiple
Documents, say, the Document data is called "a" and "b", then the
result of processing the data in each Document instance MUST be
treated as a single sequence of Media Sheets for finishing
processes; that is, the sets a(*) and b(*) would each be finished
separately. The Printer MUST force each copy of the result of
processing the data in a single Document to start on a new Media
Sheet. If more than one copy is made, the ordering of the sets of
Media Sheets resulting from processing the Document data MUST be
a(*), b(*), a(*), b(*), ... .
o 'single-document-new-sheet': Same as 'single-document', except
that the Printer MUST ensure that the first Impression of each
Document instance in the Job is placed on a new Media Sheet. This
value allows multiple Documents to be stapled together with a
single staple where each Document starts on a new Media Sheet.
The 'single-document' value is the same as
'separate-documents-collated-copies' with respect to the ordering of
Input Pages, but not Media Sheet generation, since 'single-document'
will put the first page of the next Document on the back side of a
Media Sheet if an odd number of pages have been produced so far for
the Job, while 'separate-documents-collated-copies' always forces the
next Document or Document copy on to a new Media Sheet. In addition,
if the "finishings" attribute specifies 'staple', then with
'single-document', Documents a and b are stapled together as a single
Set with no regard to a new Media Sheet, while with
'single-document-new-sheet', Documents a and b are stapled together
as a single Set but Document b starts on a new Media Sheet. With
'separate-documents-uncollated-copies' and
'separate-documents-collated-copies', Documents a and b are stapled
separately.
Note: The value 'separate-documents-uncollated-copies' produces
uncollated Media Sheets within a Set, e.g., when "copies" is '2' a
two-Document Job will be printed as Media Sheets a(1), a(1), a(2),
a(2), ... a(n), a(n), b(1), b(1), ..., b(n), b(n). All other values
produce collated Media Sheets within a Set.
The relationship of this attribute and the other attributes that
control Document processing is described in Appendix C.3.
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5.2.5. copies (integer(1:MAX))
This RECOMMENDED attribute specifies the number of copies to be
printed.
On many devices, the supported number of collated copies will be
limited by the number of physical output bins on the device and can
be different from the number of uncollated copies that can be
supported.
Note: The effect of this attribute on Jobs with multiple Documents is
controlled by the "multiple-document-handling" Job attribute
(Section 5.2.4). The relationship of this attribute and the other
attributes that control Document processing is described in
Appendix C.3.
5.2.6. finishings (1setOf type2 enum)
This RECOMMENDED attribute identifies the finishing processes that
the Printer uses for each copy of each printed Document in the Job.
For Jobs with multiple Documents, the "multiple-document-handling"
attribute determines what constitutes a "copy" for purposes of
finishing.
Standard enum values defined in this document are listed in Table 10.
The 'staple-xxx' values are specified with respect to the Document as
if the Document were in portrait orientation with the origin of each
Media Sheet at the top left corner. If the Document is actually in
landscape or reverse-landscape orientation, the Client supplies the
appropriate transformed value. For example, to position a staple in
the upper left-hand corner of a landscape Document when held for
reading, the Client supplies the 'staple-bottom-left' value, since
landscape is defined as a +90 degree rotation of the image with
respect to the media from portrait, i.e., counterclockwise. On the
other hand, to position a staple in the upper left-hand corner of a
reverse-landscape Document when held for reading, the Client supplies
the 'staple-top-right' value, since reverse-landscape is defined as
a -90 degree rotation of the image with respect to the media from
portrait, i.e., clockwise.
The angle (vertical, horizontal, angled) of each staple with respect
to the Document depends on the implementation, which can in turn
depend on the value of the attribute.
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Note: The effect of this attribute on Jobs with multiple Documents is
controlled by the "multiple-document-handling" Job attribute
(Section 5.2.4). The relationship of this attribute and the other
attributes that control Document processing is described in
Appendix C.3.
Note: The value of '3' ('none') has no effect when combined with any
other values.
Note: The "finishings-col" attribute [PWG5100.1] is an alternative to
the "finishings" attribute that allows the Client to specify
finishing intent in greater detail.
+-----------+-------------------------------------------------------+
| Value | Symbolic Name and Description |
+-----------+-------------------------------------------------------+
| '3' | 'none': Perform no finishing. |
+-----------+-------------------------------------------------------+
| '4' | 'staple': Bind the Document(s) with one or more |
| | staples. The exact number and placement of the |
| | staples are site defined. |
+-----------+-------------------------------------------------------+
| '5' | 'punch': This value indicates that holes are required |
| | in the finished Document. The exact number and |
| | placement of the holes are site defined. The punch |
| | specification MAY be satisfied (in a site-specific |
| | and implementation-specific manner) either by |
| | drilling/punching or by substituting pre-drilled |
| | media. |
+-----------+-------------------------------------------------------+
| '6' | 'cover': This value is specified when it is desired |
| | to select a non-printed (or pre-printed) cover for |
| | the Document. This does not supplant the |
| | specification of a printed cover (on cover stock |
| | medium) by the Document itself. |
+-----------+-------------------------------------------------------+
| '7' | 'bind': This value indicates that a binding is to be |
| | applied to the Document; the type and placement of |
| | the binding are site defined. |
+-----------+-------------------------------------------------------+
| '8' | 'saddle-stitch': Bind the Document(s) with one or |
| | more staples (wire stitches) along the middle fold. |
| | The exact number and placement of the staples and the |
| | middle fold are implementation defined and/or site |
| | defined. |
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+-----------+-------------------------------------------------------+
| '9' | 'edge-stitch': Bind the Document(s) with one or more |
| | staples (wire stitches) along one edge. The exact |
| | number and placement of the staples are |
| | implementation defined and/or site defined. |
+-----------+-------------------------------------------------------+
| '10'-'19' | reserved for future generic finishing enum values. |
+-----------+-------------------------------------------------------+
| '20' | 'staple-top-left': Bind the Document(s) with one or |
| | more staples in the top left corner. |
+-----------+-------------------------------------------------------+
| '21' | 'staple-bottom-left': Bind the Document(s) with one |
| | or more staples in the bottom left corner. |
+-----------+-------------------------------------------------------+
| '22' | 'staple-top-right': Bind the Document(s) with one or |
| | more staples in the top right corner. |
+-----------+-------------------------------------------------------+
| '23' | 'staple-bottom-right': Bind the Document(s) with one |
| | or more staples in the bottom right corner. |
+-----------+-------------------------------------------------------+
| '24' | 'edge-stitch-left': Bind the Document(s) with one or |
| | more staples (wire stitches) along the left edge. |
| | The exact number and placement of the staples are |
| | implementation defined and/or site defined. |
+-----------+-------------------------------------------------------+
| '25' | 'edge-stitch-top': Bind the Document(s) with one or |
| | more staples (wire stitches) along the top edge. The |
| | exact number and placement of the staples are |
| | implementation defined and/or site defined. |
+-----------+-------------------------------------------------------+
| '26' | 'edge-stitch-right': Bind the Document(s) with one or |
| | more staples (wire stitches) along the right edge. |
| | The exact number and placement of the staples are |
| | implementation defined and/or site defined. |
+-----------+-------------------------------------------------------+
| '27' | 'edge-stitch-bottom': Bind the Document(s) with one |
| | or more staples (wire stitches) along the bottom |
| | edge. The exact number and placement of the staples |
| | are implementation defined and/or site defined. |
+-----------+-------------------------------------------------------+
| '28' | 'staple-dual-left': Bind the Document(s) with two |
| | staples (wire stitches) along the left edge, assuming |
| | a portrait Document (see above). |
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+-----------+-------------------------------------------------------+
| '29' | 'staple-dual-top': Bind the Document(s) with two |
| | staples (wire stitches) along the top edge, assuming |
| | a portrait Document (see above). |
+-----------+-------------------------------------------------------+
| '30' | 'staple-dual-right': Bind the Document(s) with two |
| | staples (wire stitches) along the right edge, |
| | assuming a portrait Document (see above). |
+-----------+-------------------------------------------------------+
| '31' | 'staple-dual-bottom': Bind the Document(s) with two |
| | staples (wire stitches) along the bottom edge, |
| | assuming a portrait Document (see above). |
+-----------+-------------------------------------------------------+
Table 10: "finishings" Enum Values
5.2.7. page-ranges (1setOf rangeOfInteger(1:MAX))
This RECOMMENDED attribute identifies the range(s) of Input Pages
that the Printer uses for each Set to be printed prior to imposition
of those pages onto Impressions. Nothing is printed for any pages
identified that do not exist in the Set/Document(s). Ranges MUST be
in ascending order (1-3, 5-7, 15-19, etc.) and MUST NOT overlap so
that a non-spooling Printer can process the Job in a single pass. If
the ranges are not ascending or are overlapping, the Printer MUST
reject the request and return the 'client-error-bad-request'
status-code. The attribute is associated with Input Pages and not
application-numbered pages such as the page numbers found in the
headers and/or footers for certain word processing applications.
For Jobs with multiple Documents, the "multiple-document-handling"
attribute determines what constitutes a Set for purposes of the
specified page range(s). When "multiple-document-handling" is
'single-document', the Printer MUST apply each supplied page range
once to the concatenation of the Input Pages. For example, if there
are 8 Documents of 10 pages each, the page range '41-60' prints the
pages in the 5th and 6th Documents as a single Document, and none of
the pages of the other Documents are printed. When
"multiple-document-handling" is
'separate-documents-uncollated-copies' or
'separate-documents-collated-copies', the Printer MUST apply each
supplied page range repeatedly to each Document copy. For the same
Job, the page range '1-3, 10-10' would print the first 3 pages
and the 10th page of each of the 8 Documents in the Job, as 8
separate Sets.
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"page-ranges-supported" is a boolean value indicating whether the
Printer is capable of supporting the printing of page ranges. This
capability can differ from one PDL to another. There is no
"page-ranges-default" attribute. If the "page-ranges" attribute is
not supplied by the Client, all pages of the Document are printed.
Note: In many cases, the Client supplies only those Input Pages that
need to be printed in the Document data, and the "page-ranges" Job
Template attribute is not used. However, Clients that submit
already-generated Document data (either static content from some web
site or previously submitted content the End User wishes to reprint)
can use this attribute to print just a subset of the pages contained
in the Document. In this case, if a "page-ranges" value of 'n-m' is
specified, the first page to be printed will be page n. All
subsequent pages of the Document will be printed through and
including page m.
Note: The effect of this attribute on Jobs with multiple Documents is
controlled by the "multiple-document-handling" Job attribute
(Section 5.2.4). The relationship of this attribute and the other
attributes that control Document processing is described in
Appendix C.3.
5.2.8. sides (type2 keyword)
This RECOMMENDED attribute specifies how Impressions are placed upon
the sides of a Media Sheet.
The standard 'keyword' values are:
o 'one-sided': imposes each consecutive Impression upon the same
side of consecutive Media Sheets.
o 'two-sided-long-edge': imposes each consecutive pair of
Impressions upon front and back sides of consecutive Media Sheets,
such that the orientation of each pair of Impressions on the
medium would be correct for the reader as if for binding on the
long edge. This imposition is sometimes called 'duplex' or
'head-to-head'.
o 'two-sided-short-edge': imposes each consecutive pair of
Impressions upon front and back sides of consecutive Media Sheets,
such that the orientation of each pair of Impressions on the
medium would be correct for the reader as if for binding on the
short edge. This imposition is sometimes called 'tumble' or
'head-to-toe'.
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Note: The effect of this attribute on Jobs with multiple Documents is
controlled by the "multiple-document-handling" Job attribute
(Section 5.2.4). The relationship of this attribute and the other
attributes that control Document processing is described in
Appendix C.3.
5.2.9. number-up (integer(1:MAX))
This attribute specifies the number of Input Pages to impose upon a
single Impression. For example, if the value is:
o '1': the Printer MUST place one Input Page on a single Impression.
o '2': the Printer MUST place two Input Pages on a single
Impression.
o '4': the Printer MUST place four Input Pages on a single
Impression.
In all cases, the Printer MAY add some sort of translation, scaling,
or rotation of Input Pages when imposing them.
Note: The effect of this attribute on Jobs with multiple Documents is
controlled by the "multiple-document-handling" Job attribute
(Section 5.2.4). The relationship of this attribute and the other
attributes that control Document processing is described in
Appendix C.3.
5.2.10. orientation-requested (type2 enum)
This RECOMMENDED attribute indicates the desired orientation for
printed Input Pages; it does not describe the orientation of the
Client-supplied Input Pages.
For some Document formats (such as 'application/postscript'), the
desired orientation of the Input Pages is sometimes specified within
the Document data. This information is generated by a Printer driver
prior to the submission of the Print Job. Other Document formats
such as 'text/plain' do not include the notion of desired orientation
within the Document data. In the latter case, it is possible for the
Printer to bind the desired orientation to the Document data after it
has been submitted. Printers MAY only support
"orientation-requested" for some Document formats (e.g., 'text/plain'
or 'text/html') but not others (e.g., 'application/postscript').
This is no different than any other Job Template attribute, since
Section 5.2, item 1, points out that a Printer can support or not
support any Job Template attribute based on the Document format
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supplied by the Client. However, a special mention is made here,
since it is very likely that a Printer will support
"orientation-requested" for only a subset of the supported Document
formats.
Standard enum values are listed in Table 11.
Note: The effect of this attribute on Jobs with multiple Documents is
controlled by the "multiple-document-handling" Job attribute
(Section 5.2.4). The relationship of this attribute and the other
attributes that control Document processing is described in
Appendix C.3.
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+-------+-----------------------------------------------------------+
| Value | Symbolic Name and Description |
+-------+-----------------------------------------------------------+
| '3' | 'portrait': The content will be imaged across the short |
| | edge of the medium. |
+-------+-----------------------------------------------------------+
| '4' | 'landscape': The content will be imaged across the long |
| | edge of the medium. Landscape is defined to be a |
| | rotation of the Input Page to be imaged by +90 degrees |
| | with respect to the medium (i.e., counterclockwise) from |
| | the portrait orientation. Note: The +90 direction was |
| | chosen because simple finishing on the long edge is the |
| | same edge whether portrait or landscape. |
+-------+-----------------------------------------------------------+
| '5' | 'reverse-landscape': The content will be imaged across |
| | the long edge of the medium. Reverse-landscape is |
| | defined to be a rotation of the Input Page to be imaged |
| | by -90 degrees with respect to the medium (i.e., |
| | clockwise) from the portrait orientation. Note: The |
| | 'reverse-landscape' value was added because some |
| | applications rotate landscape -90 degrees from portrait, |
| | rather than +90 degrees. |
+-------+-----------------------------------------------------------+
| '6' | 'reverse-portrait': The content will be imaged across the |
| | short edge of the medium. Reverse-portrait is defined to |
| | be a rotation of the Input Page to be imaged by 180 |
| | degrees with respect to the medium from the portrait |
| | orientation. Note: The 'reverse-portrait' value was |
| | added for use with the "finishings" attribute in cases |
| | where the opposite edge is desired for finishing a |
| | portrait Document on simple finishing devices that have |
| | only one finishing position. Thus, a 'text'/plain' |
| | portrait Document can be stapled "on the right" by a |
| | simple finishing device, as is common use with some |
| | Middle Eastern languages such as Hebrew. |
+-------+-----------------------------------------------------------+
Table 11: "orientation-requested" Enum Values
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5.2.11. media (type2 keyword | name(MAX))
This RECOMMENDED attribute identifies the medium that the Printer
uses for all Impressions of the Job.
The values for "media" historically have included medium names,
medium sizes, input trays, and electronic forms so that one attribute
specifies the media. However, the Client SHOULD only use the media
attribute to specify medium sizes using PWG Media Standardized Names
[PWG5101.1].
If a Printer supports a medium name as a value of this attribute,
such a medium name implicitly selects an input tray that contains the
specified medium. If a Printer supports a medium size as a value of
this attribute, such a medium size implicitly selects a medium name
that in turn implicitly selects an input tray that contains the
medium with the specified size. If a Printer supports an input tray
as the value of this attribute, such an input tray implicitly selects
the medium that is in that input tray at the time the Job prints.
This case includes manual-feed input trays. If a Printer supports an
electronic form as the value of this attribute, such an electronic
form implicitly selects a medium name that in turn implicitly selects
an input tray that contains the medium specified by the electronic
form. The electronic form also implicitly selects an image that the
Printer MUST merge with the Document data as it prints each page.
PWG Media Standardized Names [PWG5101.1] SHOULD be used. Legacy
'keyword' values are taken from ISO DPA [ISO10175], the Printer MIB
[RFC3805], and ASME-Y14.1M [ASME-Y14.1M]. An Administrator MAY
define additional values using the 'name' or 'keyword' attribute
syntax, depending on implementation.
There is also an additional Printer attribute named "media-ready",
which differs from "media-supported" in that legal values only
include the subset of "media-supported" values that are physically
loaded and ready for printing with no Operator intervention required.
The relationship of this attribute and the other attributes that
control Document processing is described in Appendix C.3.
Note: If supported by the Printer, Clients MAY use the alternative
"media-col" attribute [PWG5100.3] [PWG5100.13] to specify medium
requirements in greater detail.
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5.2.12. printer-resolution (resolution)
This RECOMMENDED attribute identifies the output resolution that the
Printer uses for the Job.
Note: This attribute and the "print-quality" attribute
(Section 5.2.13) are both used to specify the overall output quality
of the Job. If a Client specifies conflicting "printer-resolution"
and "print-quality" values, Printers SHOULD use the "print-quality"
value.
5.2.13. print-quality (type2 enum)
This RECOMMENDED attribute specifies the print quality that the
Printer uses for the Job.
The standard enum values are listed in Table 12.
Note: This attribute and the "printer-resolution" attribute
(Section 5.2.12) are both used to specify the overall output quality
of the Job. If a Client specifies conflicting "printer-resolution"
and "print-quality" values, Printers SHOULD use the "print-quality"
value.
+-------+---------------------------------------------------------+
| Value | Symbolic Name and Description |
+-------+---------------------------------------------------------+
| '3' | 'draft': lowest quality available on the Printer |
+-------+---------------------------------------------------------+
| '4' | 'normal': normal or intermediate quality on the Printer |
+-------+---------------------------------------------------------+
| '5' | 'high': highest quality available on the Printer |
+-------+---------------------------------------------------------+
Table 12: "print-quality" Enum Values
5.3. Job Description and Status Attributes
The attributes in this section form the attribute group called
"job-description". Tables 13 and 14 summarize these attributes. The
third column of each table indicates whether the attribute is a
REQUIRED attribute that MUST be supported by Printers. If it is not
indicated as REQUIRED, then it is OPTIONAL. The maximum size in
octets for 'text' and 'name' attributes is indicated in parentheses.
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+------------------+----------------+-----------+
| Attribute | Syntax | REQUIRED? |
+------------------+----------------+-----------+
| job-impressions | integer(0:MAX) | |
+------------------+----------------+-----------+
| job-k-octets | integer(0:MAX) | |
+------------------+----------------+-----------+
| job-media-sheets | integer(1:MAX) | |
+------------------+----------------+-----------+
| job-name | name(MAX) | REQUIRED |
+------------------+----------------+-----------+
Table 13: Job Description Attributes (READ-WRITE)
+-----------------------------+-------------------------+-----------+
| Attribute | Syntax | REQUIRED? |
+-----------------------------+-------------------------+-----------+
| attributes-charset | charset | REQUIRED |
+-----------------------------+-------------------------+-----------+
| attributes-natural-language | naturalLanguage | REQUIRED |
+-----------------------------+-------------------------+-----------+
| date-time-at-completed | dateTime|unknown|no- | |
| | value | |
+-----------------------------+-------------------------+-----------+
| date-time-at-creation | dateTime|unknown | |
+-----------------------------+-------------------------+-----------+
| date-time-at-processing | dateTime|unknown|no- | |
| | value | |
+-----------------------------+-------------------------+-----------+
| job-detailed-status- | 1setOf text(MAX) | |
| messages | | |
+-----------------------------+-------------------------+-----------+
| job-document-access-errors | 1setOf text(MAX) | |
+-----------------------------+-------------------------+-----------+
| job-id | integer(1:MAX) | REQUIRED |
+-----------------------------+-------------------------+-----------+
| job-impressions-completed | integer(0:MAX) | |
+-----------------------------+-------------------------+-----------+
| job-k-octets-processed | integer(0:MAX) | |
+-----------------------------+-------------------------+-----------+
| job-media-sheets-completed | integer(0:MAX) | |
+-----------------------------+-------------------------+-----------+
| job-message-from-operator | text(127) | |
+-----------------------------+-------------------------+-----------+
| job-more-info | uri | |
+-----------------------------+-------------------------+-----------+
| job-originating-user-name | name(MAX) | REQUIRED |
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+-----------------------------+-------------------------+-----------+
| job-printer-up-time | integer(1:MAX) | REQUIRED |
+-----------------------------+-------------------------+-----------+
| job-printer-uri | uri | REQUIRED |
+-----------------------------+-------------------------+-----------+
| job-state | type1 enum | REQUIRED |
+-----------------------------+-------------------------+-----------+
| job-state-message | text(MAX) | |
+-----------------------------+-------------------------+-----------+
| job-state-reasons | 1setOf type2 keyword | REQUIRED |
+-----------------------------+-------------------------+-----------+
| job-uri | uri | REQUIRED |
+-----------------------------+-------------------------+-----------+
| number-of-documents | integer(0:MAX) | |
+-----------------------------+-------------------------+-----------+
| number-of-intervening-jobs | integer(0:MAX) | |
+-----------------------------+-------------------------+-----------+
| output-device-assigned | name(127) | |
+-----------------------------+-------------------------+-----------+
| time-at-completed | integer(MIN:MAX) | REQUIRED |
+-----------------------------+-------------------------+-----------+
| time-at-creation | integer(MIN:MAX) | REQUIRED |
+-----------------------------+-------------------------+-----------+
| time-at-processing | integer(MIN:MAX) | REQUIRED |
+-----------------------------+-------------------------+-----------+
Table 14: Job Status Attributes (READ-ONLY)
5.3.1. job-id (integer(1:MAX))
This REQUIRED attribute contains the ID of the Job. The Printer, on
receipt of a new Job, generates an ID that identifies the new Job on
that Printer. The Printer returns the value of the "job-id"
attribute as part of the response to a Job Creation request.
For a description of this attribute and its relationship to the
"job-uri" and "job-printer-uri" attributes, see the discussion in
Section 3.4 ("Object Identity").
5.3.2. job-uri (uri)
This REQUIRED attribute contains the URI for the Job. The Printer,
on receipt of a new Job, generates a URI that identifies the new Job.
The Printer returns the value of the "job-uri" attribute as part of
the response to a Job Creation request. The precise format of a Job
URI is implementation dependent [RFC3510] [RFC7472]. If the Printer
supports more than one URI and there is some relationship between the
newly formed Job URI and the Printer's URI, the Printer uses the
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Printer URI supplied by the Client in the Job Creation request. For
example, if the Job Creation request comes in over a secure channel,
the new Job URI MUST use the same secure channel. This can be
guaranteed because the Printer is responsible for generating the Job
URI and the Printer is aware of its security configuration and policy
as well as the Printer URI used in the Job Creation request.
For a description of this attribute and its relationship to the
"job-id" and "job-printer-uri" attributes, see the discussion in
Section 3.4 ("Object Identity").
5.3.3. job-printer-uri (uri)
This REQUIRED attribute identifies the Printer that created this Job.
When a Printer creates a Job, it populates this attribute with the
Printer URI that was used in the Job Creation request. This
attribute permits a Client to identify the Printer that created this
Job when only the Job's URI is available to the Client. The Client
queries the creating Printer to determine which languages, charsets,
and operations are supported for this Job.
For a description of this attribute and its relationship to the
"job-uri" and "job-id" attributes, see the discussion in Section 3.4
("Object Identity").
5.3.4. job-more-info (uri)
Similar to "printer-more-info", this attribute contains the URI
referencing some resource with more information about this Job,
perhaps an HTML page containing status information about the Job.
5.3.5. job-name (name(MAX))
This REQUIRED attribute is the name of the Job. It is a name that is
more user friendly than the "job-uri" or "job-id" attribute values.
It does not need to be unique between Jobs. The Job's "job-name"
attribute is set to the value supplied by the Client in the
"job-name" operation attribute in the Job Creation request (see
Section 4.2.1.1). If, however, the "job-name" operation attribute is
not supplied by the Client in the Job Creation request, the Printer,
on creation of the Job, MUST generate a name. The Printer SHOULD
generate the value of the Job's "job-name" attribute from the first
of the following sources that produces a value: (1) the
"document-name" operation attribute of the first (or only) Document,
(2) the "document-URI" attribute of the first (or only) Document, or
(3) any other piece of Job-specific and/or Document data.
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5.3.6. job-originating-user-name (name(MAX))
This REQUIRED attribute contains the name of the End User that
submitted the Print Job. The Printer sets this attribute to the most
authenticated printable name that it can obtain from the
authentication service over which the IPP operation was received.
Only if such a name is not available does the Printer use the value
supplied by the Client in the "requesting-user-name" operation
attribute of the Job Creation request (see Sections 5.4.2, 5.4.3,
and 9).
Note: The Printer needs to keep an internal originating user ID of
some form, typically as a credential of a principal, with the Job.
Since such an internal attribute is implementation dependent and not
of interest to Clients, it is not specified as a Job attribute. This
originating user ID is used for authorization checks (if any) on all
subsequent operations.
5.3.7. job-state (type1 enum)
This REQUIRED attribute identifies the current state of the Job.
Even though IPP defines seven values for Job states (plus the
out-of-band 'unknown' value -- see Section 5.1), implementations only
need to support those states that are appropriate for the particular
implementation. In other words, a Printer supports only those Job
states implemented by the Output Device and available to the Printer
implementation.
Standard enum values are listed in Table 15.
The final value for this attribute MUST be one of the following --
'completed', 'canceled', or 'aborted' -- before the Printer removes
the Job altogether. The length of time that Jobs remain in the
'canceled', 'aborted', and 'completed' states depends on
implementation. See Section 5.3.7.2.
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Figure 3 shows the normal Job state transitions. Normally, a Job
progresses from left to right. Other state transitions are unlikely
but are not forbidden. Not shown are the transitions to the
'canceled' state from the 'pending', 'pending-held', and
'processing-stopped' states.
+----> canceled
/
+----> pending -------> processing ---------+------> completed
| ^ ^ \
--->+ | | +----> aborted
| v v /
+----> pending-held processing-stopped ---+
Figure 3: IPP Job Life Cycle
Jobs reach one of the three terminal states -- 'completed',
'canceled', or 'aborted' -- after the Jobs have completed all
activity, including stacking output media, and all Job Status
attributes have reached their final values for the Job.
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+--------+----------------------------------------------------------+
| Values | Symbolic Name and Description |
+--------+----------------------------------------------------------+
| '3' | 'pending': The Job is a candidate to start processing |
| | but is not yet processing. |
+--------+----------------------------------------------------------+
| '4' | 'pending-held': The Job is not a candidate for |
| | processing for any number of reasons but will return to |
| | the 'pending' state as soon as the reasons are no longer |
| | present. The Job's "job-state-reasons" attribute MUST |
| | indicate why the Job is no longer a candidate for |
| | processing. |
+--------+----------------------------------------------------------+
| '5' | 'processing': One or more of the following: (1) the Job |
| | is using, or is attempting to use, one or more purely |
| | software processes that are analyzing, creating, or |
| | interpreting a PDL, etc.; (2) the Job is using, or is |
| | attempting to use, one or more hardware devices that are |
| | interpreting a PDL; making marks on a medium; and/or |
| | performing finishing, such as stapling, etc.; (3) the |
| | Printer has made the Job ready for printing, but the |
| | Output Device is not yet printing it, either because the |
| | Job hasn't reached the Output Device or because the Job |
| | is queued in the Output Device or some other spooler, |
| | waiting for the Output Device to print it. When the Job |
| | is in the 'processing' state, the entire Job state |
| | includes the detailed status represented in the |
| | Printer's "printer-state", "printer-state-reasons", and |
| | "printer-state-message" attributes. Implementations MAY |
| | include additional values in the Job's "job-state- |
| | reasons" attribute to indicate the progress of the Job, |
| | such as adding the 'job-printing' value to indicate when |
| | the Output Device is actually making marks on paper |
| | and/or the 'processing-to-stop-point' value to indicate |
| | that the Printer is in the process of canceling or |
| | aborting the Job. |
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+--------+----------------------------------------------------------+
| '6' | 'processing-stopped': The Job has stopped while |
| | processing for any number of reasons and will return to |
| | the 'processing' state as soon as the reasons are no |
| | longer present. The Job's "job-state-reasons" attribute |
| | MAY indicate why the Job has stopped processing. For |
| | example, if the Output Device is stopped, the 'printer- |
| | stopped' value MAY be included in the Job's "job-state- |
| | reasons" attribute. Note: When an Output Device is |
| | stopped, the device usually indicates its condition in |
| | human-readable form locally at the device. A Client can |
| | obtain more complete device status remotely by querying |
| | the Printer's "printer-state", "printer-state-reasons", |
| | and "printer-state-message" attributes. |
+--------+----------------------------------------------------------+
| '7' | 'canceled': The Job has been canceled by a Cancel-Job |
| | operation, and the Printer has completed canceling the |
| | Job. All Job Status attributes have reached their final |
| | values for the Job. While the Printer is canceling the |
| | Job, the Job remains in its current state, but the Job's |
| | "job-state-reasons" attribute SHOULD contain the |
| | 'processing-to-stop-point' value and one of the |
| | 'canceled-by-user', 'canceled-by-operator', or |
| | 'canceled-at-device' values. When the Job moves to the |
| | 'canceled' state, the 'processing-to-stop-point' value, |
| | if present, MUST be removed, but 'canceled-by-xxx', if |
| | present, MUST remain. |
+--------+----------------------------------------------------------+
| '8' | 'aborted': The Job has been aborted by the system, |
| | usually while the Job was in the 'processing' or |
| | 'processing-stopped' state, and the Printer has |
| | completed aborting the Job; all Job Status attributes |
| | have reached their final values for the Job. While the |
| | Printer is aborting the Job, the Job remains in its |
| | current state, but the Job's "job-state-reasons" |
| | attribute SHOULD contain the 'processing-to-stop-point' |
| | and 'aborted-by-system' values. When the Job moves to |
| | the 'aborted' state, the 'processing-to-stop-point' |
| | value, if present, MUST be removed, but the 'aborted-by- |
| | system' value, if present, MUST remain. |
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+--------+----------------------------------------------------------+
| '9' | 'completed': The Job has completed successfully or with |
| | warnings or errors after processing, all of the Job |
| | Media Sheets have been successfully stacked in the |
| | appropriate output bin(s), and all Job Status attributes |
| | have reached their final values for the Job. The Job's |
| | "job-state-reasons" attribute SHOULD contain one of the |
| | 'completed-successfully', 'completed-with-warnings', or |
| | 'completed-with-errors' values. |
+--------+----------------------------------------------------------+
Table 15: "job-state" Enum Values
5.3.7.1. Forwarding Servers
As with all other IPP attributes, if the implementation cannot
determine the correct value for this attribute, it SHOULD respond
with the out-of-band 'unknown' value (see Section 5.1) rather than
try to guess at some possibly incorrect value and confuse the
End User about the state of the Job. For example, if the
implementation is just a gateway into some printing system from which
it can normally get status, but temporarily is unable, then the
implementation should return the 'unknown' value. However, if the
implementation is a gateway to a printing system that never provides
detailed status about the Print Job, the implementation MAY set the
IPP Job's state to 'completed', provided that it also sets the
'queued-in-device' value in the Job's "job-state-reasons" attribute
(see Section 5.3.8).
5.3.7.2. Partitioning of Job States
This section describes the partitioning of the seven Job states into
phases: Job Not Completed, Job Retention, Job History, and Job
Removal. This section also explains the 'job-restartable' value of
the "job-state-reasons" Job Status attribute for use with the
Restart-Job and Resubmit-Job [PWG5100.11] operations.
Job Not Completed: When a Job is in the 'pending', 'pending-held',
'processing', or 'processing-stopped' state, the Job is not
completed.
Job Retention: When a Job enters one of the three terminal Job states
-- 'completed', 'canceled', or 'aborted' -- the IPP Printer MAY
"retain" the Job in a restartable condition for an implementation-
defined time period. This time period MAY be zero seconds and MAY
depend on the terminal Job state. This phase is called "Job
Retention". While in the Job Retention phase, the Job's Document
data is retained and a Client can restart the Job using the
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Restart-Job operation. If the Printer supports the Restart-Job or
Resubmit-Job operation, then it SHOULD indicate that the Job is
restartable by adding the 'job-restartable' value to the Job's
"job-state-reasons" attribute (see Section 5.3.8) during the Job
Retention phase.
Job History: After the Job Retention phase expires for a Job, the
Printer deletes the Document data for the Job and the Job becomes
part of the Job History. The Printer MAY also delete any number of
the Job attributes. Since the Job is no longer restartable, the
Printer MUST remove the 'job-restartable' value from the Job's
"job-state-reasons" attribute, if present. Printers SHOULD keep the
Job in the Job History phase for at least 60 seconds to allow Clients
to discover the final disposition of the Job.
Job Removal: After the Job has remained in the Job History for an
implementation-defined time, such as when the number of Jobs exceeds
a fixed number or after a fixed time period (which MAY be
zero seconds), the IPP Printer removes the Job from the system.
Using the Get-Jobs operation and supplying the 'not-completed' value
for the "which-jobs" operation attribute, a Client is requesting Jobs
in the Job Not Completed phase. Using the Get-Jobs operation and
supplying the 'completed' value for the "which-jobs" operation
attribute, a Client is requesting Jobs in the Job Retention and Job
History phases. Using the Get-Job-Attributes operation, a Client is
requesting a Job in any phase except Job Removal. After Job Removal,
the Get-Job-Attributes and Get-Jobs operations no longer are capable
of returning any information about a Job.
5.3.8. job-state-reasons (1setOf type2 keyword)
This REQUIRED attribute provides additional information about the
Job's current state, i.e., information that augments the value of the
Job's "job-state" attribute.
These values MAY be used with any Job state or states for which the
reason makes sense. Some of these value definitions indicate
conformance requirements; the rest are OPTIONAL. Furthermore, when
implemented, the Printer MUST return these values when the reason
applies and MUST NOT return them when the reason no longer applies,
whether the value of the Job's "job-state" attribute changed or not.
When the Job does not have any reasons for being in its current
state, the value of the Job's "job-state-reasons" attribute MUST be
'none'.
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Note: While values cannot be added to the "job-state" attribute
without impacting deployed Clients that take actions upon receiving
"job-state" values, it is the intent that additional
"job-state-reasons" values can be defined and registered without
impacting such deployed Clients. In other words, the
"job-state-reasons" attribute is intended to be extensible.
The following standard 'keyword' values are defined. For ease of
understanding, the values are presented in the order in which the
reasons are likely to occur (if implemented):
o 'none': There are no reasons for the Job's current state. This
state reason is semantically equivalent to "job-state-reasons"
without any value and MUST be used when there is no other value,
since the '1setOf' attribute syntax requires at least one value.
o 'job-incoming': Either (1) the Printer has accepted the Create-Job
operation and is expecting additional Send-Document and/or
Send-URI operations or (2) the Printer is retrieving/accepting
Document data as a result of a Print-Job, Print-URI,
Send-Document, or Send-URI operation.
o 'job-data-insufficient': The Create-Job operation has been
accepted by the Printer, but the Printer is expecting additional
Document data before it can move the Job into the 'processing'
state. If a Printer starts processing before it has received all
data, the Printer removes the 'job-data-insufficient' reason, but
the 'job-incoming' reason remains. If a Printer starts processing
after it has received all data, the Printer removes the
'job-data-insufficient' reason and the 'job-incoming' reason at
the same time.
o 'document-access-error': After accepting a Print-URI or Send-URI
request, the Printer could not access one or more Documents passed
by reference. This reason is intended to cover any file access
problem, including 'file does not exist' and 'access denied'
because of an access control problem. The Printer MAY also
indicate the Document access error using the
"job-document-access-errors" Job Status attribute (see
Section 5.3.11). The Printer can (1) abort the Job and move the
Job to the 'aborted' Job state or (2) print all Documents that are
accessible and move the Job to the 'completed' Job state with the
'completed-with-errors' value in the Job's "job-state-reasons"
attribute. This value SHOULD be supported if the Print-URI or
Send-URI operations are supported.
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o 'submission-interrupted': The Job was not completely submitted for
some unforeseen reason, such as (1) the Printer has crashed before
the Job was closed by the Client, (2) the Printer or the Document
transfer method has crashed in some non-recoverable way before the
Document data was entirely transferred to the Printer, or (3) the
Client crashed or failed to close the Job before the time-out
period. See Section 5.4.31.
o 'job-outgoing': The Printer is transmitting the Job to the Output
Device.
o 'job-hold-until-specified': The value of the Job's
"job-hold-until" attribute was specified with a time period that
is still in the future. The Job MUST NOT be a candidate for
processing until this reason is removed and there are no other
reasons to hold the Job. This value SHOULD be supported if the
"job-hold-until" Job Template attribute is supported.
o 'resources-are-not-ready': At least one of the resources needed by
the Job, such as media, fonts, resource objects, etc., is not
ready on any of the physical Output Devices for which the Job is a
candidate. This condition MAY be detected when the Job is
accepted, or subsequently while the Job is pending or processing,
depending on implementation. The Job can remain in its current
state or be moved to the 'pending-held' state, depending on
implementation and/or Job scheduling policy.
o 'printer-stopped-partly': The value of the Printer's
"printer-state-reasons" attribute contains the value
'stopped-partly'.
o 'printer-stopped': The value of the Printer's "printer-state"
attribute is 'stopped'.
o 'job-interpreting': The Job is in the 'processing' state, but,
more specifically, the Printer is interpreting the Document data.
o 'job-queued': The Job is in the 'processing' state, but, more
specifically, the Printer has queued the Document data.
o 'job-transforming': The Job is in the 'processing' state, but,
more specifically, the Printer is interpreting Document data and
producing another electronic representation.
o 'job-queued-for-marker': The Job is in any of the 'pending-held',
'pending', or 'processing' states, but, more specifically, the
Printer has completed enough processing of the Document to be able
to start marking, and the Job is waiting for the marker. Systems
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that require human intervention to release Jobs using the
Release-Job operation put the Job into the 'pending-held' Job
state. Systems that automatically select a Job to use the marker
put the Job into the 'pending' Job state or keep the Job in the
'processing' Job state while waiting for the marker, depending on
implementation. All implementations put the Job into the
'processing' state when marking does begin.
o 'job-printing': The Output Device is marking media. This value is
useful for Printers that spend a great deal of time processing
(1) when no marking is happening and they want to show that
marking is now happening or (2) when the Job is in the process of
being canceled or aborted while the Job remains in the
'processing' state, but the marking has not yet stopped so that
Impression or sheet counts are still increasing for the Job.
o 'job-canceled-by-user': The Job was canceled by the owner of the
Job using the Cancel-Job request, i.e., by a user whose
authenticated identity is the same as the value of the originating
user that created the Job, or by some other authorized End User,
such as a member of the Job owner's security group. This value
SHOULD be supported.
o 'job-canceled-by-operator': The Job was canceled by the Operator
using the Cancel-Job request, i.e., by a user who has been
authenticated as having Operator privileges (whether local or
remote). If the security policy is to allow anyone to cancel
anyone's Job, then this value can be used when the Job is canceled
by other than the owner of the Job. For such a security policy,
in effect, everyone is an Operator as far as canceling Jobs with
IPP is concerned. This value SHOULD be supported if the
implementation permits canceling by other than the owner of
the Job.
o 'job-canceled-at-device': The Job was canceled by an unidentified
local user, i.e., a user at a console at the device. This value
SHOULD be supported if the implementation supports canceling Jobs
at the console.
o 'aborted-by-system': The Job (1) is in the process of being
aborted, (2) has been aborted by the system and placed in the
'aborted' state, or (3) has been aborted by the system and placed
in the 'pending-held' state, so that a user or Operator can
manually try the Job again. This value SHOULD be supported.
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o 'unsupported-compression': The Job was aborted by the system
because the Printer determined, while attempting to decompress the
Document data, that the compression algorithm is actually not
among those supported by the Printer. This value MUST be
supported, since "compression" is a REQUIRED operation attribute.
o 'compression-error': The Job was aborted by the system because the
Printer encountered an error in the Document data while
decompressing it. If the Printer posts this reason, the Document
data has already passed any tests that would have led to the
'unsupported-compression' "job-state-reasons" value.
o 'unsupported-document-format': The Job was aborted by the system
because the Document data's "document-format" attribute is not
among those supported by the Printer. If the Client specifies
"document-format" as 'application/octet-stream', the Printer MAY
abort the Job and post this reason even though the
"document-format" value is among the values of the Printer's
"document-format-supported" Printer attribute but not among the
auto-sensed Document formats. This value MUST be supported, since
"document-format" is a REQUIRED operation attribute.
o 'document-format-error': The Job was aborted by the system because
the Printer encountered an error in the Document data while
processing it. If the Printer posts this reason, the Document
data has already passed any tests that would have led to the
'unsupported-document-format' "job-state-reasons" value.
o 'processing-to-stop-point': The requester has issued a Cancel-Job
operation or the Printer has aborted the Job, but the Printer is
still performing some actions on the Job until a specified stop
point occurs or Job termination/cleanup is completed.
If the implementation requires some measurable time to cancel the
Job in the 'processing' or 'processing-stopped' Job state, the
Printer MUST use this value to indicate that the Printer is still
performing some actions on the Job while the Job remains in the
'processing' or 'processing-stopped' state. Once at the stop
point, the Printer moves the Job from the 'processing' state to
the 'canceled' or 'aborted' Job state.
o 'service-off-line': The Printer is offline and accepting no Jobs.
All 'pending' Jobs are put into the 'pending-held' state. This
situation could be true if the service's or Document transform's
input is impaired or broken.
o 'job-completed-successfully': The Job completed successfully.
This value SHOULD be supported.
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o 'job-completed-with-warnings': The Job completed with warnings.
This value SHOULD be supported if the implementation detects
warnings.
o 'job-completed-with-errors': The Job completed with errors (and
possibly warnings too). This value SHOULD be supported if the
implementation detects errors.
o 'job-restartable': This Job is retained (see Section 5.3.7.2) and
is currently able to be restarted using the Restart-Job (see
Section 4.3.7) or Resubmit-Job [PWG5100.11] operation. If
'job-restartable' is a value of the Job's "job-state-reasons"
attribute, then the Printer MUST accept a Restart-Job operation
for that Job. This value SHOULD be supported if the Restart-Job
operation is supported.
o 'queued-in-device': The Job has been forwarded to a device or
print system that is unable to send back status. The Printer sets
the Job's "job-state" attribute to 'completed' and adds the
'queued-in-device' value to the Job's "job-state-reasons"
attribute to indicate that the Printer has no additional
information about the Job and never will have any better
information. See Section 5.3.7.1.
5.3.9. job-state-message (text(MAX))
This RECOMMENDED attribute specifies information about the
"job-state" and "job-state-reasons" attributes in human-readable
text. If the Printer supports this attribute, the Printer MUST be
able to generate this message in any of the natural languages
identified by the Printer's "generated-natural-language-supported"
attribute (see the "attributes-natural-language" operation attribute
specified in Section 4.1.4.1).
The value SHOULD NOT contain additional information not contained in
the values of the "job-state" and "job-state-reasons" attributes,
such as interpreter error information. Otherwise, application
programs might attempt to parse the (localized) text. For such
additional information, such as interpreter errors for application
program consumption or specific Document access errors, new
attributes with 'keyword' values need to be developed and registered.
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5.3.10. job-detailed-status-messages (1setOf text(MAX))
This attribute specifies additional detailed and technical
information about the Job. The Printer SHOULD localize the message,
unless such localization would obscure the technical meaning of the
message. Clients MUST NOT attempt to parse the value of this
attribute. See "job-document-access-errors" (Section 5.3.11) for
additional errors that a program can process.
5.3.11. job-document-access-errors (1setOf text(MAX))
This attribute provides additional information about each Document
access error for this Job encountered by the Printer after it
returned a response to the Print-URI or Send-URI operation and
subsequently attempted to access document(s) supplied in the
Print-URI or Send-URI operation. For errors in the protocol that is
identified by the URI scheme in the "document-uri" operation
attribute, such as 'http:' or 'ftp:', the error code is returned in
parentheses, followed by the URI. For example:
(404) http://www.example.com/filename.pdf
Most Internet protocols use decimal error codes (unlike IPP), so the
ASCII error code representation is in decimal.
5.3.12. number-of-documents (integer(0:MAX))
This attribute indicates the number of Documents in the Job, i.e.,
the number of Send-Document, Send-URI, Print-Job, or Print-URI
operations that the Printer has accepted for this Job, regardless of
whether the Document data has reached the Printer.
Implementations supporting the RECOMMENDED Create-Job/Send-Document/
Send-URI operations SHOULD support this attribute so that Clients can
query the number of Documents in each Job.
5.3.13. output-device-assigned (name(127))
This attribute identifies the Output Device to which the Printer has
assigned this Job. If an Output Device implements an embedded
Printer, the Printer SHOULD set this attribute. If a print server
implements a Printer, the value MAY be empty (zero-length string) or
not returned until the Printer assigns an Output Device to the Job.
This attribute is particularly useful when a single Printer supports
multiple devices (so-called "fan-out" -- see Section 3.1).
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5.3.14. Event Time Job Status Attributes
This section defines the Job Status attributes that indicate the time
at which certain events occur for a Job. If the Job event has not
yet occurred, then the Printer MUST return the 'no-value' out-of-band
value (see the beginning of Section 5.1). The
"time-at-xxx (integer)" attributes represent time as an 'integer'
representing the number of seconds since the device was powered up
(informally called "time ticks"). The "date-time-at-xxx (dateTime)"
attributes represent time as 'dateTime' representing date and time
(including an offset from UTC).
In order to populate these attributes, the Printer copies the
value(s) of the following Printer Status attributes at the time the
event occurs:
1. the value in the Printer's "printer-up-time" attribute for the
"time-at-xxx (integer)" attributes.
2. the value in the Printer's "printer-current-time" attribute for
the "date-time-at-xxx (dateTime)" attributes.
If the Printer resets its "printer-up-time" attribute to 1 on
power-up (see Section 5.4.29) and has persistent Jobs, then it MUST
change all of those Jobs' "time-at-xxx (integer)" (time tick) Job
attributes whose events have occurred either to:
1. 0 to indicate that the event happened before the most recent
power-up, or
2. the negative of the number of seconds before the most recent
power-up that the event took place, if the Printer knows the
exact number of seconds.
If a Client queries a "time-at-xxx (integer)" time tick Job attribute
and finds the value to be 0 or negative, the Client MUST assume that
the event occurred in some life other than the Printer's current
life.
Note: A Printer does not change the values of any
"date-time-at-xxx (dateTime)" Job attributes on power-up.
5.3.14.1. time-at-creation (integer(MIN:MAX))
This REQUIRED attribute indicates the time at which the Job was
created.
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5.3.14.2. time-at-processing (integer(MIN:MAX))
This REQUIRED attribute indicates the time at which the Job first
began processing after the Job Creation request or the most recent
Restart-Job operation. The out-of-band 'no-value' value is returned
if the Job has not yet been in the 'processing' state (see the
beginning of Section 5.1).
5.3.14.3. time-at-completed (integer(MIN:MAX))
This REQUIRED attribute indicates the time at which the Job entered a
Terminating State ('completed', 'canceled', or 'aborted'). The
out-of-band 'no-value' value is returned if the Job has not yet
completed, been canceled, or aborted (see the beginning of
Section 5.1).
5.3.14.4. job-printer-up-time (integer(1:MAX))
This REQUIRED Job Status attribute indicates the amount of time (in
seconds) that the Printer implementation has been up and running.
This attribute is an alias for the "printer-up-time" Printer Status
attribute (see Section 5.4.29).
A Client MAY request this attribute in a Get-Job-Attributes or
Get-Jobs request and use the value returned in combination with other
requested Event Time Job Status attributes in order to display time
attributes to a user. The difference between this attribute and the
'integer' value of a "time-at-xxx" attribute is the number of seconds
ago that the "time-at-xxx" event occurred. A Client can compute the
wall-clock time at which the "time-at-xxx" event occurred by
subtracting this difference from the Client's wall-clock time.
5.3.14.5. date-time-at-creation (dateTime|unknown)
This RECOMMENDED attribute indicates the date and time at which the
Job was created.
5.3.14.6. date-time-at-processing (dateTime|unknown|no-value)
This RECOMMENDED attribute indicates the date and time at which the
Job first began processing after the Job Creation request or the most
recent Restart-Job operation.
5.3.14.7. date-time-at-completed (dateTime|unknown|no-value)
This RECOMMENDED attribute indicates the date and time at which the
Job entered a Terminating State ('completed', 'canceled', or
'aborted').
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5.3.15. number-of-intervening-jobs (integer(0:MAX))
This attribute indicates the number of Jobs that are "ahead" of this
Job in the relative chronological order of expected time to complete
(i.e., the current scheduled order). For efficiency, it is only
necessary to calculate this value when an operation is performed that
requests this attribute.
5.3.16. job-message-from-operator (text(127))
This attribute provides a message from an Operator, Administrator, or
"intelligent" process to indicate to the End User the reasons for
modification or other management action taken on a Job.
5.3.17. Job Size Attributes
This subsection defines Job attributes that describe the size of the
Job. These attributes are not intended to be counters; they are
intended to be useful routing and scheduling information if known.
For these attributes, the Printer can try to compute the value if it
is not supplied in the Job Creation request. Even if the Client does
supply a value for these three attributes in the Job Creation
request, the Printer MAY choose to change the value if the Printer is
able to compute a value that is more accurate than the
Client-supplied value. The Printer can determine the correct value
for these attributes either right at Job submission time or at any
later point in time.
5.3.17.1. job-k-octets (integer(0:MAX))
This attribute specifies the total size of the Document(s) in
K octets, i.e., in units of 1024 octets requested to be processed
in the Job. The value MUST be rounded up, so that a Job between
1 and 1024 octets MUST be indicated as being 1, 1025 to 2048 MUST
be 2, etc.
This value MUST NOT include the multiplicative factors contributed by
the number of copies specified by the "copies" attribute, independent
of whether the device can process multiple copies without making
multiple passes over the Job or Document data and independent of
whether the output is collated or not. Thus, the value is
independent of the implementation and indicates the size of the
Document(s) measured in K octets independent of the number of copies.
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This value also MUST NOT include the multiplicative factor due to a
copies instruction embedded in the Document data. If the Document
data actually includes replications of the Document data, this value
will include such replication. In other words, this value is always
the size of the source Document data, rather than a measure of the
hardcopy output to be produced.
5.3.17.2. job-impressions (integer(0:MAX))
This RECOMMENDED attribute specifies the total size in number of
Impressions of the Document(s) being submitted (see the definition of
"Impression" in Section 2.3.4).
As with "job-k-octets", this value MUST NOT include the
multiplicative factors contributed by the number of copies specified
by the "copies" attribute, independent of whether the device can
process multiple copies without making multiple passes over the Job
or Document data and independent of whether the output is collated or
not. Thus, the value is independent of the implementation and
reflects the size of the Document(s) measured in Impressions
independent of the number of copies.
As with "job-k-octets", this value also MUST NOT include the
multiplicative factor due to a copies instruction embedded in the
Document data. If the Document data actually includes replications
of the Document data, this value will include such replication. In
other words, this value is always the number of Impressions in the
source Document data, rather than a measure of the number of
Impressions to be produced by the Job.
5.3.17.3. job-media-sheets (integer(1:MAX))
This RECOMMENDED attribute specifies the total number of Media Sheets
to be produced for this Job.
Unlike the "job-k-octets" and the "job-impressions" attributes, this
value MUST include the multiplicative factors contributed by the
number of copies specified by the "copies" attribute and a 'number of
copies' instruction embedded in the Document data, if any. This
difference allows the Administrator to control the lower and upper
bounds of both (1) the size of the Document(s) with
"job-k-octets-supported" and "job-impressions-supported" and
(2) the size of the Job with "job-media-sheets-supported".
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5.3.18. Job Progress Attributes
This subsection defines Job attributes that describe the progress of
the Job. These attributes are intended to be counters. That is, the
values for a Job that has not started processing MUST be 0. When the
Job's "job-state" is 'processing' or 'processing-stopped', this value
is intended to contain the amount of the Job that has been processed
to the time at which the attributes are requested. When the Job
enters the 'completed', 'canceled', or 'aborted' states, these values
are the final values for the Job.
5.3.18.1. job-k-octets-processed (integer(0:MAX))
This attribute specifies the total number of octets processed in
K octets, i.e., in units of 1024 octets so far. The value MUST be
rounded up, so that a Job between 1 and 1024 octets inclusive MUST be
indicated as being 1, 1025 to 2048 inclusive MUST be 2, etc.
For implementations where multiple copies are produced by the
interpreter with only a single pass over the data, the final value
MUST be equal to the value of the "job-k-octets" attribute. For
implementations where multiple copies are produced by the interpreter
by processing the data for each copy, the final value MUST be a
multiple of the value of the "job-k-octets" attribute.
5.3.18.2. job-impressions-completed (integer(0:MAX))
This RECOMMENDED attribute specifies the number of Impressions
completed for the Job so far. For printing devices, the Impressions
completed includes interpreting, marking, and stacking the output.
5.3.18.3. job-media-sheets-completed (integer(0:MAX))
This RECOMMENDED Job attribute specifies the number of Media Sheets
that have been marked and stacked for the entire Job so far, whether
those sheets have been processed on one side or on both.
5.3.19. attributes-charset (charset)
This REQUIRED attribute is populated using the value in the
Client-supplied "attributes-charset" attribute in the Job Creation
request. It identifies the charset (coded character set and encoding
method) used by any Job attributes with attribute syntaxes 'text' and
'name' that were supplied by the Client in the Job Creation request.
See Section 4.1.4 for a complete description of the
"attributes-charset" operation attribute.
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This attribute does not indicate the charset in which the 'text' and
'name' values are stored internally in the Job. The internal charset
is implementation defined. The Printer MUST convert from whatever
the internal charset is to that being requested in an operation as
specified in Section 4.1.4.
5.3.20. attributes-natural-language (naturalLanguage)
This REQUIRED attribute is populated using the value in the
Client-supplied "attributes-natural-language" attribute in the Job
Creation request. It identifies the natural language used for any
Job attributes with attribute syntaxes 'text' and 'name' that were
supplied by the Client in the Job Creation request. See
Section 4.1.4 for a complete description of the
"attributes-natural-language" operation attribute. See
Sections 5.1.2.2 and 5.1.3.2 for how a Natural Language Override can
be supplied explicitly for each 'text' and 'name' attribute value
that differs from the value identified by the
"attributes-natural-language" attribute.
5.4. Printer Description and Status Attributes
These attributes form the attribute group called
"printer-description". Tables 16 and 17 summarize these attributes,
their syntax, and whether they are REQUIRED for a Printer to support.
If they are not indicated as REQUIRED, they are OPTIONAL. The
maximum size in octets for 'text' and 'name' attributes is indicated
in parentheses.
Note: How these attributes are set by an Administrator is outside the
scope of this document.
+-----------------------------+-----------------------+-------------+
| Attribute | Syntax | REQUIRED? |
+-----------------------------+-----------------------+-------------+
| charset-configured | charset | REQUIRED |
+-----------------------------+-----------------------+-------------+
| charset-supported | 1setOf charset | REQUIRED |
+-----------------------------+-----------------------+-------------+
| color-supported | boolean | RECOMMENDED |
+-----------------------------+-----------------------+-------------+
| compression-supported | 1setOf type2 keyword | REQUIRED |
+-----------------------------+-----------------------+-------------+
| document-format-default | mimeMediaType | REQUIRED |
+-----------------------------+-----------------------+-------------+
| document-format-supported | 1setOf mimeMediaType | REQUIRED |
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+-----------------------------+-----------------------+-------------+
| generated-natural-language- | 1setOf | REQUIRED |
| supported | naturalLanguage | |
+-----------------------------+-----------------------+-------------+
| ipp-versions-supported | 1setOf type2 keyword | REQUIRED |
+-----------------------------+-----------------------+-------------+
| job-impressions-supported | rangeOfInteger(0:MAX) | RECOMMENDED |
+-----------------------------+-----------------------+-------------+
| job-k-octets-supported | rangeOfInteger(0:MAX) | |
+-----------------------------+-----------------------+-------------+
| job-media-sheets-supported | rangeOfInteger(1:MAX) | |
+-----------------------------+-----------------------+-------------+
| multiple-document-jobs- | boolean | RECOMMENDED |
| supported | | |
+-----------------------------+-----------------------+-------------+
| multiple-operation-time-out | integer(1:MAX) | RECOMMENDED |
+-----------------------------+-----------------------+-------------+
| natural-language-configured | naturalLanguage | REQUIRED |
+-----------------------------+-----------------------+-------------+
| operations-supported | 1setOf type2 enum | REQUIRED |
+-----------------------------+-----------------------+-------------+
| pdl-override-supported | type2 keyword | REQUIRED |
+-----------------------------+-----------------------+-------------+
| printer-driver-installer | uri | |
+-----------------------------+-----------------------+-------------+
| printer-info | text(127) | RECOMMENDED |
+-----------------------------+-----------------------+-------------+
| printer-location | text(127) | RECOMMENDED |
+-----------------------------+-----------------------+-------------+
| printer-make-and-model | text(127) | RECOMMENDED |
+-----------------------------+-----------------------+-------------+
| printer-message-from- | text(127) | |
| operator | | |
+-----------------------------+-----------------------+-------------+
| printer-more-info- | uri | |
| manufacturer | | |
+-----------------------------+-----------------------+-------------+
| printer-name | name(127) | REQUIRED |
+-----------------------------+-----------------------+-------------+
| reference-uri-schemes- | 1setOf uriScheme | |
| supported | | |
+-----------------------------+-----------------------+-------------+
Table 16: Printer Description Attributes (READ-WRITE)
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+------------------------------+----------------------+-------------+
| Attribute | Syntax | REQUIRED? |
+------------------------------+----------------------+-------------+
| pages-per-minute-color | integer(0:MAX) | RECOMMENDED |
+------------------------------+----------------------+-------------+
| pages-per-minute | integer(0:MAX) | RECOMMENDED |
+------------------------------+----------------------+-------------+
| printer-current-time | dateTime|unknown | RECOMMENDED |
+------------------------------+----------------------+-------------+
| printer-is-accepting-jobs | boolean | REQUIRED |
+------------------------------+----------------------+-------------+
| printer-more-info | uri | RECOMMENDED |
+------------------------------+----------------------+-------------+
| printer-state | type1 enum | REQUIRED |
+------------------------------+----------------------+-------------+
| printer-state-message | text(MAX) | RECOMMENDED |
+------------------------------+----------------------+-------------+
| printer-state-reasons | 1setOf type2 keyword | REQUIRED |
+------------------------------+----------------------+-------------+
| printer-up-time | integer(1:MAX) | REQUIRED |
+------------------------------+----------------------+-------------+
| printer-uri-supported | 1setOf uri | REQUIRED |
+------------------------------+----------------------+-------------+
| queued-job-count | integer(0:MAX) | REQUIRED |
+------------------------------+----------------------+-------------+
| uri-authentication-supported | 1setOf type2 keyword | REQUIRED |
+------------------------------+----------------------+-------------+
| uri-security-supported | 1setOf type2 keyword | REQUIRED |
+------------------------------+----------------------+-------------+
Table 17: Printer Status Attributes (READ-ONLY)
5.4.1. printer-uri-supported (1setOf uri)
This REQUIRED Printer attribute contains one or more URIs for the
Printer. It MAY contain more than one URI for the Printer. An
Administrator determines a Printer's URIs and configures this
attribute to contain those URIs by some means outside the scope of
this IPP/1.1 document. The precise format of the URIs is
implementation dependent and depends on the protocol. See
Sections 5.4.2 and 5.4.3 for a description of the
"uri-authentication-supported" and "uri-security-supported"
attributes, both of which are the REQUIRED companion attributes to
this "printer-uri-supported" attribute. See Sections 3.4 ("Object
Identity") and 9.2 ("URIs in Operation, Job, and Printer Attributes")
for more information.
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5.4.2. uri-authentication-supported (1setOf type2 keyword)
This REQUIRED Printer attribute MUST have the same cardinality
(contain the same number of values) as the "printer-uri-supported"
attribute. This attribute identifies the Client Authentication
mechanism associated with each URI listed in the
"printer-uri-supported" attribute. The Printer uses the specified
mechanism to identify the authenticated user (see Section 9.3). The
"i-th" value in "uri-authentication-supported" corresponds to the
"i-th" value in "printer-uri-supported", and it describes the
authentication mechanisms used by the Printer when accessed via that
URI. See [RFC8010] for more details on Client Authentication.
The following standard 'keyword' values are defined:
o 'none': There is no authentication mechanism associated with the
URI. The Printer assumes that the authenticated user is
'anonymous'.
o 'requesting-user-name': When a Client performs an operation whose
target is the associated URI, the Printer assumes that the
authenticated user is specified by the "requesting-user-name"
operation attribute (see Section 9.3). If the
"requesting-user-name" attribute is absent in a request, the
Printer assumes that the authenticated user is 'anonymous'.
o 'basic': When a Client performs an operation whose target is the
associated URI, the Printer challenges the Client with HTTP Basic
authentication [RFC7617]. The Printer assumes that the
authenticated user is the name received via the Basic
authentication mechanism.
o 'digest': When a Client performs an operation whose target is the
associated URI, the Printer challenges the Client with HTTP Digest
authentication [RFC7616]. The Printer assumes that the
authenticated user is the name received via the Digest
authentication mechanism.
o 'certificate': When a Client performs an operation whose target is
the associated URI, the Printer expects the Client to provide an
X.509 certificate. The Printer assumes that the authenticated
user is one of the textual names (Common Name or Subject Alternate
Names) contained within the certificate.
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5.4.3. uri-security-supported (1setOf type2 keyword)
This REQUIRED Printer attribute MUST have the same cardinality
(contain the same number of values) as the "printer-uri-supported"
attribute. This attribute identifies the security mechanisms used
for each URI listed in the "printer-uri-supported" attribute. The
"i-th" value in "uri-security-supported" corresponds to the "i-th"
value in "printer-uri-supported", and it describes the security
mechanisms used for accessing the Printer via that URI. See
[RFC8010] for more details on security mechanisms.
The following standard 'keyword' values are defined:
o 'none': There are no secure communication channel protocols in use
for the given URI.
o 'tls': TLS [RFC5246] [RFC7525] is the secure communications
channel protocol in use for the given URI.
This attribute is orthogonal to the definition of a Client
Authentication mechanism. Specifically, 'none' does not exclude
Client Authentication. See Section 5.4.2.
Consider the following example. For a single Printer, an
Administrator configures the "printer-uri-supported",
"uri-authentication-supported", and "uri-security-supported"
attributes as follows:
"printer-uri-supported": 'ipp://printer.example.com/ipp/print/
open-use-printer', 'ipp://printer.example.com/ipp/print/
restricted-use-printer', 'ipps://printer.example.com/ipp/print/
private-printer'
"uri-authentication-supported": 'none', 'digest', 'basic'
"uri-security-supported": 'none', 'none', 'tls'
In this case, one Printer has three URIs.
o For the first URI, 'ipp://printer.example.com/ipp/print/
open-use-printer', the value 'none' in "uri-security-supported"
indicates that there is no secure channel protocol configured to
run under HTTP. The value of 'none' in
"uri-authentication-supported" indicates that all users are
'anonymous'. There will be no challenge, and the Printer will
ignore "requesting-user-name".
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o For the second URI, 'ipp://printer.example.com/ipp/print/
restricted-use-printer', the value 'none' in
"uri-security-supported" indicates that there is no secure channel
protocol configured to run under HTTP. The value of 'digest' in
"uri-authentication-supported" indicates that the Printer will
issue a challenge and that the Printer will use the name supplied
by the Digest mechanism to determine the authenticated user (see
Section 9.3).
o For the third URI, 'ipps://printer.example.com/ipp/print/
private-printer', the value 'tls' in "uri-security-supported"
indicates that TLS is being used to secure the channel. The
Client SHOULD be prepared to use TLS framing to negotiate an
acceptable ciphersuite to use while communicating with the
Printer. In this case, the name implies the use of a secure
communications channel, but the fact is made explicit by the
presence of the 'tls' value in "uri-security-supported". The
Client does not need to resort to understanding which security
mechanisms it must use by following naming conventions or by
parsing the URI to determine which security mechanisms are
implied. The value of 'basic' in "uri-authentication-supported"
indicates that the Printer will issue a challenge and that the
Printer will use the name supplied by the Basic mechanism to
determine the authenticated user (see Section 9.3). Because this
challenge occurs in a TLS session, the channel is secure.
Some Printers will be configured to support only one channel (either
configured to use TLS access or not) and only one authentication
mechanism. Such Printers only have one URI listed in the
"printer-uri-supported" attribute. No matter the configuration of
the Printer (whether it has only one URI or more than one URI), a
Client MUST supply only one URI in the target "printer-uri" operation
attribute.
5.4.4. printer-name (name(127))
This REQUIRED Printer attribute contains the name of the Printer. It
is a name that is more End User friendly than a URI. An
Administrator determines a Printer's name and sets this attribute to
that name. This name can be the last part of the Printer's URI, or
it can be unrelated. In non-US-English locales, a name can contain
characters that are not allowed in a URI.
5.4.5. printer-location (text(127))
This RECOMMENDED Printer attribute identifies the location of the
device. This could include things like 'in Room 123A, second floor
of building XYZ'.
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5.4.6. printer-info (text(127))
This RECOMMENDED Printer attribute provides descriptive information
about this Printer. This could include things like 'This printer can
be used for printing color transparencies for HR presentations', or
'Out of courtesy for others, please print only small (1-5 page) jobs
at this printer', or even 'This printer is going away on July 1;
please find a new printer'.
5.4.7. printer-more-info (uri)
This RECOMMENDED Printer attribute contains a URI used to obtain more
information about this specific Printer. For example, this could be
an HTTP URI referencing an HTML page accessible to a web browser.
The information obtained from this URI is intended for End User
consumption. Features outside the scope of IPP can be accessed from
this URI. The information is intended to be specific to this Printer
instance and site-specific services, e.g., Job pricing, services
offered, and End User assistance. The device manufacturer can
initially populate this attribute.
5.4.8. printer-driver-installer (uri)
This Printer attribute contains a URI to use to locate the driver
installer for this Printer. This attribute is intended for
consumption by automata. The mechanics of Printer driver
installation are outside the scope of this document. The device
manufacturer can initially populate this attribute.
5.4.9. printer-make-and-model (text(127))
This RECOMMENDED Printer attribute identifies the make and model of
the device. The device manufacturer can initially populate this
attribute.
5.4.10. printer-more-info-manufacturer (uri)
This Printer attribute contains a URI used to obtain more information
about this type of device. The information obtained from this URI is
intended for End User consumption. Features outside the scope of IPP
can be accessed from this URI (e.g., latest firmware, upgrades,
Printer drivers, optional features available, details on color
support). The information is intended to be germane to this Printer
without regard to site-specific modifications or services. The
device manufacturer can initially populate this attribute.
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5.4.11. printer-state (type1 enum)
This REQUIRED Printer attribute identifies the current state of the
device. The "printer-state reasons" attribute augments the
"printer-state" attribute to give more detailed information about the
Printer in the given Printer state.
A Printer updates this attribute continually if asynchronous event
notification [RFC3995] is supported.
Standard enum values are defined in Table 18. Values of
"printer-state-reasons", such as 'spool-area-full' and
'stopped-partly', MAY be used to provide further information.
+-------+-----------------------------------------------------------+
| Value | Symbolic Name and Description |
+-------+-----------------------------------------------------------+
| '3' | 'idle': Indicates that new Jobs can start processing |
| | without waiting. |
+-------+-----------------------------------------------------------+
| '4' | 'processing': Indicates that Jobs are processing; new |
| | Jobs will wait before processing. |
+-------+-----------------------------------------------------------+
| '5' | 'stopped': Indicates that no Jobs can be processed and |
| | intervention is required. |
+-------+-----------------------------------------------------------+
Table 18: "printer-state" Enum Values
5.4.12. printer-state-reasons (1setOf type2 keyword)
This REQUIRED Printer attribute supplies additional detail about the
device's state. Some of the value definitions indicate conformance
requirements; the rest are OPTIONAL.
Each 'keyword' value MAY have a suffix to indicate its level of
severity. The three levels are 'report' (least severe), 'warning',
and 'error' (most severe):
o '-report': This suffix indicates that the reason is a "report".
An implementation can choose to omit some or all reports. Some
reports specify finer granularity about the Printer state; others
serve as a precursor to a warning. A report MUST contain nothing
that could affect the printed output. Reports correspond to the
'other' value for the prtAlertSeverityLevel property in the
Printer MIB [RFC3805].
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o '-warning': This suffix indicates that the reason is a "warning".
An implementation can choose to omit some or all warnings.
Warnings serve as a precursor to an error. A warning MUST contain
nothing that prevents a Job from completing, though in some cases
the output can be of lower quality. Warnings correspond to the
'warning' value for the prtAlertSeverityLevel property in the
Printer MIB [RFC3805].
o '-error': This suffix indicates that the reason is an "error". An
implementation MUST include all errors. If this attribute
contains one or more errors, the Printer MUST be in the 'stopped'
state. Errors correspond to the 'critical' value for the
prtAlertSeverityLevel property in the Printer MIB [RFC3805].
If the implementation does not add any one of the three suffixes and
the value is not 'none', Clients can assume that the reason is an
"error" if the Printer is in the 'stopped' state and a "warning" if
the Printer is in any other state.
If a Printer controls more than one Output Device, each value of this
attribute MAY apply to one or more of the Output Devices. An error
on one Output Device that does not stop the Printer as a whole MAY
appear as a warning in the Printer's "printer-state-reasons"
attribute. If "printer-state" for such a Printer has a value of
'stopped', then there MUST be an error reason among the values in the
"printer-state-reasons" attribute.
The following standard 'keyword' values are defined:
o 'none': There are no reasons. This state reason is semantically
equivalent to "printer-state-reasons" without any value and MUST
be used, since the '1setOf' attribute syntax requires at least one
value.
o 'other': The device has detected a condition other than one listed
in this document.
o 'connecting-to-device': The Printer has scheduled a Job on the
Output Device and is in the process of connecting to a shared
network Output Device (and might not be able to actually start
printing the Job for an arbitrarily long time, depending on the
usage of the Output Device by other servers on the network).
o 'cover-open': One or more covers on the device are open,
equivalent to a prtCoverStatus [RFC3805] of 3 (coverOpen).
o 'developer-empty: The device is out of developer.
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o 'developer-low': The device is low on developer.
o 'door-open': One or more doors on the device are open, equivalent
to a prtCoverStatus [RFC3805] of 3 (coverOpen).
o 'fuser-over-temp': The fuser temperature is above normal,
equivalent to a prtMarkerStatus [RFC3805] of 19 (the sum of
"Unavailable because Broken" (3) and "Critical Alerts" (16)).
o 'fuser-under-temp': The fuser temperature is below normal,
equivalent to a prtMarkerStatus [RFC3805] of 19 (the sum of
"Unavailable because Broken" (3) and "Critical Alerts" (16)).
o 'input-tray-missing': One or more input trays are not in the
device, equivalent to a prtInputStatus [RFC3805] of 19 (the sum of
"Unavailable because Broken" (3) and "Critical Alerts" (16)).
o 'interlock-open': One or more interlock devices on the Printer are
unlocked, equivalent to a prtCoverStatus [RFC3805] of 5
(interlockOpen).
o 'interpreter-resource-unavailable': An interpreter resource is
unavailable (i.e., font, form).
o 'marker-supply-empty: The device is out of at least one marker
supply, e.g., toner, ink, ribbon.
o 'marker-supply-low': The device is low on at least one marker
supply, e.g., toner, ink, ribbon.
o 'marker-waste-almost-full': The device marker supply waste
receptacle is almost full.
o 'marker-waste-full': The device marker supply waste receptacle is
full.
o 'media-empty': At least one input tray is empty, equivalent to a
prtInputStatus [RFC3805] of 19 (the sum of "Unavailable because
Broken" (3) and "Critical Alerts" (16)).
o 'media-jam': The device has a media jam, equivalent to a
prtInputStatus [RFC3805] of 19 (the sum of "Unavailable because
Broken" (3) and "Critical Alerts" (16)).
o 'media-low': At least one input tray is low on media, equivalent
to a prtInputStatus [RFC3805] of 8 (Non-Critical Alerts).
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o 'media-needed': A tray has run out of media, equivalent to a
prtInputStatus [RFC3805] value of 17 (the sum of "Unavailable and
OnRequest" (1) and "Critical Alerts" (16)).
o 'moving-to-paused': Someone has paused the Printer using the
Pause-Printer operation (see Section 4.2.7) or other means, but
the device(s) is taking an appreciable time to stop. Later, when
all output has stopped, "printer-state" becomes 'stopped', and the
'paused' value replaces the 'moving-to-paused' value in the
"printer-state-reasons" attribute. This value MUST be supported
if the Pause-Printer operation is supported and the implementation
takes significant time to pause a device in certain circumstances.
o 'opc-life-over': The optical photo conductor is no longer
functioning, equivalent to a prtMarkerStatus [RFC3805] of 19
(the sum of "Unavailable because Broken" (3) and
"Critical Alerts" (16)).
o 'opc-near-eol': The optical photo conductor is near its end of
life, equivalent to a prtMarkerStatus [RFC3805] of 8 (Non-Critical
Alerts).
o 'output-area-almost-full': One or more output areas are almost
full, e.g., tray, stacker, collator, equivalent to a
prtOutputStatus [RFC3805] of 8 (Non-Critical Alerts).
o 'output-area-full': One or more output areas are full, e.g., tray,
stacker, collator, equivalent to a prtInputStatus [RFC3805] of 19
(the sum of "Unavailable because Broken" (3) and
"Critical Alerts" (16)).
o 'output-tray-missing': One or more output trays are not in the
device, equivalent to a prtOutputStatus [RFC3805] of 19 (the sum
of "Unavailable because Broken" (3) and "Critical Alerts" (16)).
o 'paused': Someone has paused the Printer using the Pause-Printer
operation (see Section 4.2.7) or other means, and the Printer's
"printer-state" is 'stopped'. In this state, a Printer MUST NOT
produce printed output, but it MUST perform other operations
requested by a Client. If a Printer had been printing a Job when
the Printer was paused, the Printer MUST resume printing that Job
when the Printer is no longer paused and leave no evidence in the
printed output of such a pause. This value MUST be supported if
the Pause-Printer operation is supported.
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o 'shutdown': Someone has removed a Printer from service, and the
device can be powered down or physically removed. In this state,
a Printer MUST NOT produce printed output, and unless the Printer
is realized by a print server that is still active, the Printer
MUST perform no other operations requested by a Client, including
returning this value. If a Printer had been printing a Job when
it was shut down, the Printer MAY resume printing that Job when
the Printer is restarted. If the Printer resumes printing such a
Job, it can leave evidence in the printed output of such a
shutdown, e.g., the part printed before the shutdown can be
printed a second time after the shutdown.
o 'spool-area-full': The limit of persistent storage allocated for
spooling has been reached. The Printer is temporarily unable to
accept more Jobs. The Printer will remove this value when it is
able to accept more Jobs. This value SHOULD be used by a
non-spooling Printer that only accepts one or a small number of
Jobs at a time or by a spooling Printer that has filled the spool
space.
o 'stopped-partly': When a Printer controls more than one Output
Device, this reason indicates that one or more Output Devices are
stopped. If the reason is a report, fewer than half of the Output
Devices are stopped. If the reason is a warning, fewer than all
of the Output Devices are stopped.
o 'stopping': The Printer is in the process of stopping the device
and will be stopped in a while. When the device is stopped, the
Printer will change the Printer's state to 'stopped'. The
'stopping-warning' reason is never an error, even for a Printer
with a single Output Device. When an Output Device ceases
accepting Jobs, the Printer will have this reason while the Output
Device completes printing.
o 'timed-out': The server was able to connect to the Output Device
(or is always connected) but was unable to get a response from the
Output Device.
o 'toner-empty': The device is out of toner.
o 'toner-low': The device is low on toner.
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5.4.13. printer-state-message (text(MAX))
This RECOMMENDED Printer attribute specifies information about the
"printer-state" and "printer-state-reasons" attributes in human-
readable text. If the Printer supports this attribute, the Printer
MUST be able to generate this message in any of the natural languages
identified by the Printer's "generated-natural-language-supported"
attribute (see the "attributes-natural-language" operation attribute
specified in Section 4.1.4.1).
5.4.14. ipp-versions-supported (1setOf type2 keyword)
This REQUIRED attribute identifies the IPP version(s) that this
Printer supports, including major and minor versions, i.e., the
version numbers for which this Printer implementation meets the
conformance requirements. For version number validation, the Printer
matches the (2-octet binary) "version-number" parameter supplied by
the Client in each request (see Sections 4.1.1 and 4.1.8) with the
(US-ASCII) 'keyword' values of this attribute.
The following standard 'keyword' values are defined in this document:
o '1.0': Meets the conformance requirements of IPP version 1.0 as
specified in RFC 2566 [RFC2566] and RFC 2565 [RFC2565], including
any extensions registered according to Section 7 and any extension
defined in this version or any future version of the IPP Model and
Semantics document (this document) or the IPP Encoding and
Transport document [RFC8010] following the rules, if any, when the
"version-number" parameter is '1.0'.
o '1.1': Meets the conformance requirements of IPP version 1.1 as
specified in this document and [RFC8010], including any extensions
registered according to Section 7 and any extension defined in any
future versions of this document or [RFC8010] following the rules,
if any, when the "version-number" parameter is '1.1'.
Additional values are defined in "IPP Version 2.0, 2.1, and 2.2"
[PWG5100.12].
5.4.15. operations-supported (1setOf type2 enum)
This REQUIRED Printer attribute specifies the set of supported
operations for this Printer and contained Jobs.
This attribute is encoded as any other enum attribute syntax
according to [RFC8010] as 32 bits. However, all 32-bit enum values
for this attribute MUST NOT exceed 0x00007fff, since these same
values are also passed in two octets in the "operation-id" field (see
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Section 4.1.1) in each Protocol request with the two high-order
octets omitted in order to indicate the operation being performed
[RFC8010].
Table 19 lists the "operations-supported" attribute and
"operation-id" parameter (see Section 4.1.2) enum values that are
defined in this document.
+---------------+---------------------------------------------------+
| Value | Operation Name |
+---------------+---------------------------------------------------+
| 0x0000 | reserved, not used |
+---------------+---------------------------------------------------+
| 0x0001 | reserved, not used |
+---------------+---------------------------------------------------+
| 0x0002 | Print-Job |
+---------------+---------------------------------------------------+
| 0x0003 | Print-URI |
+---------------+---------------------------------------------------+
| 0x0004 | Validate-Job |
+---------------+---------------------------------------------------+
| 0x0005 | Create-Job |
+---------------+---------------------------------------------------+
| 0x0006 | Send-Document |
+---------------+---------------------------------------------------+
| 0x0007 | Send-URI |
+---------------+---------------------------------------------------+
| 0x0008 | Cancel-Job |
+---------------+---------------------------------------------------+
| 0x0009 | Get-Job-Attributes |
+---------------+---------------------------------------------------+
| 0x000a | Get-Jobs |
+---------------+---------------------------------------------------+
| 0x000b | Get-Printer-Attributes |
+---------------+---------------------------------------------------+
| 0x000c | Hold-Job |
+---------------+---------------------------------------------------+
| 0x000d | Release-Job |
+---------------+---------------------------------------------------+
| 0x000e | Restart-Job |
+---------------+---------------------------------------------------+
| 0x000f | reserved for a future operation |
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+---------------+---------------------------------------------------+
| 0x0010 | Pause-Printer |
+---------------+---------------------------------------------------+
| 0x0011 | Resume-Printer |
+---------------+---------------------------------------------------+
| 0x0012 | Purge-Jobs |
+---------------+---------------------------------------------------+
| 0x0013-0x3fff | additional registered operations (see the IANA |
| | IPP registry and Section 7.8) |
+---------------+---------------------------------------------------+
| 0x4000-0x7fff | reserved for vendor extensions (see Section 7.8) |
+---------------+---------------------------------------------------+
Table 19: "operations-supported" Enum Values
5.4.16. multiple-document-jobs-supported (boolean)
This RECOMMENDED Printer attribute indicates whether the Printer
supports more than one Document per Job, i.e., more than one
Send-Document operation with Document data and/or Send-URI
operations. If the Printer supports the Create-Job and Send-Document
operations (see Sections 4.2.4 and 4.3.1), it MUST support this
attribute.
5.4.17. charset-configured (charset)
This REQUIRED Printer attribute identifies the charset that the
Printer has been configured to represent 'text' and 'name' Printer
attributes that are set by the Operator, Administrator, or
manufacturer, i.e., for "printer-name" (name), "printer-location"
(text), "printer-info" (text), and "printer-make-and-model" (text).
Therefore, the value of the Printer's "charset-configured" attribute
MUST also be among the values of the Printer's "charset-supported"
attribute.
5.4.18. charset-supported (1setOf charset)
This REQUIRED Printer attribute identifies the set of charsets that
the Printer and contained Jobs support in attributes with attribute
syntaxes 'text' and 'name'. At least the value 'utf-8' MUST be
present, since IPP objects MUST support the UTF-8 [RFC3629] charset.
If a Printer supports a charset, it means that for all attributes of
syntaxes 'text' and 'name' the Printer MUST (1) accept the charset in
requests and (2) return the charset in responses as needed.
If more charsets than UTF-8 are supported, the Printer MUST perform
charset conversion between the charsets as described in
Section 4.1.4.2.
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5.4.19. natural-language-configured (naturalLanguage)
This REQUIRED Printer attribute identifies the natural language that
the Printer has been configured to represent 'text' and 'name'
Printer attributes that are set by the Operator, Administrator, or
manufacturer, i.e., for "printer-name" (name), "printer-location"
(text), "printer-info" (text), and "printer-make-and-model" (text).
When returning these Printer attributes, the Printer MAY return them
in the configured natural language specified by this attribute,
instead of the natural language requested by the Client in the
"attributes-natural-language" operation attribute. See
Section 4.1.4.1 for the specification of the OPTIONAL support for
multiple natural languages. Therefore, the value of the Printer's
"natural-language-configured" attribute MUST also be among the values
of the Printer's "generated-natural-language-supported" attribute.
5.4.20. generated-natural-language-supported (1setOf naturalLanguage)
This REQUIRED Printer attribute identifies the natural language(s)
that the Printer and contained Jobs support in attributes with
attribute syntaxes 'text' and 'name'. The natural language(s)
supported depends on implementation and/or configuration. Unlike
charsets, Printers MUST accept requests with any natural language or
any Natural Language Override whether the natural language is
supported or not.
If a Printer supports a natural language, it means that for any of
the attributes for which the Printer or Job generates messages, i.e.,
for the "job-state-message" and "printer-state-message" attributes
and operation messages (see Section 4.1.5) in operation responses,
the Printer and Job MUST be able to generate messages in any of the
Printer's supported natural languages. See Sections 4.1.4, 5.1.2,
and 5.1.3 for the definitions of 'text' and 'name' attributes in
operation requests and responses.
Note: A Printer that supports multiple natural languages often has
separate catalogs of messages, one for each natural language
supported.
5.4.21. document-format-default (mimeMediaType)
This REQUIRED Printer attribute identifies the Document format that
the Printer has been configured to assume if the Client does not
supply a "document-format" operation attribute in any of the
operation requests that supply Document data. The standard values
for this attribute are Internet media types (sometimes called "MIME
media types"). For further details, see the description of the
'mimeMediaType' attribute syntax in Section 5.1.10.
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5.4.22. document-format-supported (1setOf mimeMediaType)
This REQUIRED Printer attribute identifies the set of Document
formats that the Printer and contained Jobs can support. For further
details, see the description of the 'mimeMediaType' attribute syntax
in Section 5.1.10.
5.4.23. printer-is-accepting-jobs (boolean)
This REQUIRED Printer attribute indicates whether the Printer is
currently able to accept Jobs, i.e., is accepting Print-Job,
Print-URI, and Create-Job requests. If the value is 'true', the
Printer is accepting Jobs. If the value is 'false', the Printer is
currently rejecting any Jobs submitted to it. In this case, the
Printer returns the 'server-error-not-accepting-jobs' status-code.
This value is independent of the "printer-state" and
"printer-state-reasons" attributes because its value does not affect
the current Job; rather, it affects future Jobs. This attribute,
when 'false', causes the Printer to reject Jobs even when
"printer-state" is 'idle' or, when 'true', causes the Printer to
accept Jobs even when "printer-state" is 'stopped'.
5.4.24. queued-job-count (integer(0:MAX))
This REQUIRED Printer attribute contains a count of the number of
Jobs that are either 'pending', 'processing', 'pending-held', or
'processing-stopped' and is set by the Printer.
5.4.25. printer-message-from-operator (text(127))
This Printer attribute provides a message from an Operator,
Administrator, or "intelligent" process to indicate to the End User
information or status of the Printer, such as why it is unavailable
or when it is expected to be available.
5.4.26. color-supported (boolean)
This RECOMMENDED Printer attribute identifies whether the device is
capable of any type of color printing at all, including highlight
color. All Document instructions having to do with color are
embedded within the Document PDL, although IPP attributes can affect
the rendering of those colors.
Note: End Users are able to determine the nature and details of the
color support by querying the "printer-more-info-manufacturer"
Printer attribute.
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5.4.27. reference-uri-schemes-supported (1setOf uriScheme)
This Printer attribute specifies which URI schemes are supported for
use in the "document-uri" operation attribute of the Print-URI or
Send-URI operations. If a Printer supports these OPTIONAL
operations, it MUST support the "reference-uri-schemes-supported"
Printer attribute with at least the following URI scheme value:
o 'ftp': The Printer will use an FTP 'get' operation as defined in
[RFC959] using FTP URLs as defined by [RFC3986].
The Printer MAY support other URI schemes (see Section 5.1.7).
5.4.28. pdl-override-supported (type2 keyword)
This REQUIRED Printer attribute expresses the ability of a particular
Printer implementation to override Document data instructions with
IPP attributes. The following 'keyword' values are defined in this
document:
o 'attempted': This value indicates that the Printer attempts to
make the IPP attribute values take precedence over embedded
instructions in the Document data; however, there is no guarantee.
o 'not-attempted': This value indicates that the Printer makes no
attempt to make the IPP attribute values take precedence over
embedded instructions in the Document data.
Appendix C contains a full description of how this attribute
interacts with and affects other IPP attributes, especially the
"ipp-attribute-fidelity" attribute.
5.4.29. printer-up-time (integer(1:MAX))
This REQUIRED Printer attribute indicates the amount of time (in
seconds) that this Printer instance has been up and running. The
value is a monotonically increasing value starting from 1 when the
Printer is started up (initialized, booted, etc.). This value is
used to populate the Event Time Job Status attributes
"time-at-creation", "time-at-processing", and "time-at-completed"
(see Section 5.3.14).
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If the Printer goes down at some value 'n' and comes back up, the
implementation MAY:
1. know how long it has been down and resume at some value greater
than 'n', or
2. restart from 1.
In other words, if the device or devices that the Printer is
representing are restarted or power-cycled, the Printer MAY continue
counting this value or MAY reset this value to 1, depending on
implementation. However, if the Printer software ceases running and
restarts without knowing the last value for "printer-up-time", the
implementation MUST reset this value to 1. If this value is reset
and the Printer has persistent Jobs, the Printer MUST reset the
"time-at-xxx (integer)" Event Time Job Status attributes according to
Section 5.3.14. An implementation MAY use both implementation
alternatives, depending on warm versus cold start, respectively.
5.4.30. printer-current-time (dateTime|unknown)
This RECOMMENDED Printer attribute indicates the current date and
time. This value is used to populate the Event Time Job Status
attributes "date-time-at-creation", "date-time-at-processing", and
"date-time-at-completed" (see Section 5.3.14).
This value is obtained on a "best effort" basis and in practice does
not have to be precise in order to be useful. A Printer
implementation sets the value of this attribute by obtaining the date
and time via some implementation-dependent means, such as getting the
value from a network time server, initialization at time of
manufacture, or setting by an Administrator. See [RFC3196] and
[PWG5100.19] for examples. If an implementation supports this
attribute and the implementation knows that it has not yet been set,
then the implementation MUST return the value of this attribute using
the out-of-band 'unknown', meaning the value is not yet known. See
the beginning of Section 5.1.
The time zone of this attribute might not be the time zone used by
people located near the Printer or device. The Client MUST NOT
expect the time zone of any received 'dateTime' value to be in the
time zone of the Client or in the time zone of the people located
near the Printer.
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The Client SHOULD display any dateTime attributes to the user in the
Client's local time by converting the 'dateTime' value returned by
the server to the time zone of the Client, rather than using the time
zone returned by the Printer in attributes that use the 'dateTime'
attribute syntax.
Note: Prior versions of this document incorrectly specified the use
of the 'no-value' out-of-band value when the current date and time
had not been set. The correct out-of-band value is 'unknown', since
there is always an intrinsic current date and time.
5.4.31. multiple-operation-time-out (integer(1:MAX))
This RECOMMENDED Printer attribute identifies the minimum time (in
seconds) that the Printer waits for additional Send-Document or
Send-URI operations to follow a still-open Job before taking any
recovery actions, such as the ones indicated in Section 4.3.1. If
the Printer supports the Create-Job and Send-Document operations (see
Sections 4.2.4 and 4.3.1), it MUST support this attribute.
Printers SHOULD use a value between '60' and '240' (seconds). An
implementation MAY allow an Administrator to set this attribute by
means not defined in this document. If so, the Administrator MAY be
able to set values outside this range.
5.4.32. compression-supported (1setOf type2 keyword)
This REQUIRED Printer attribute identifies the set of supported
compression algorithms for Document data. Compression only applies
to the Document data; compression does not apply to the encoding of
the IPP operation itself. The supported values are used to validate
the Client-supplied "compression" operation attributes in Print-Job
and Send-Document requests.
Standard 'keyword' values defined in this document are:
o 'none': no compression is used.
o 'deflate': ZIP inflate/deflate compression technology described in
RFC 1951 [RFC1951].
o 'gzip': GNU zip compression technology described in RFC 1952
[RFC1952].
o 'compress': UNIX compression technology described in RFC 1977
[RFC1977].
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5.4.33. job-k-octets-supported (rangeOfInteger(0:MAX))
This Printer attribute specifies the upper and lower bounds of total
sizes of Jobs in K octets, i.e., in units of 1024 octets. The
supported values are used to validate the Client-supplied
"job-k-octets" operation attribute in Job Creation requests. The
corresponding Job Description attribute "job-k-octets" is defined in
Section 5.3.17.1.
5.4.34. job-impressions-supported (rangeOfInteger(0:MAX))
This RECOMMENDED Printer attribute specifies the upper and lower
bounds for the number of Impressions per Job. The supported values
are used to validate the Client-supplied "job-impressions" operation
attribute in Job Creation requests. The corresponding Job
Description attribute "job-impressions" is defined in
Section 5.3.17.2.
5.4.35. job-media-sheets-supported (rangeOfInteger(1:MAX))
This Printer attribute specifies the upper and lower bounds for the
number of Media Sheets per Job. The supported values are used to
validate the Client-supplied "job-media-sheets" operation attribute
in Job Creation requests. The corresponding Job attribute
"job-media-sheets" is defined in Section 5.3.17.3.
5.4.36. pages-per-minute (integer(0:MAX))
This RECOMMENDED Printer attribute specifies the nominal number of
pages per minute to the nearest whole number that can be generated by
this Printer (e.g., simplex, black-and-white). This attribute is
informative, not a service guarantee. Generally, it is the value
used in the marketing literature to describe the speed of the device.
A value of 0 indicates a device that takes more than two minutes to
process a page.
5.4.37. pages-per-minute-color (integer(0:MAX))
This RECOMMENDED Printer attribute specifies the nominal number of
pages per minute to the nearest whole number that can be generated by
this Printer when printing color (e.g., simplex, color). For
purposes of this attribute, the meaning of "color" is the same as
that for the "color-supported" attribute; namely, the device is
capable of any type of color printing at all, including highlight
color. This attribute is informative, not a service guarantee.
Generally, it is the value used in the marketing literature to
describe the color capabilities of this device.
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A value of 0 indicates a device that takes more than two minutes to
process a page in color.
If a color device has several color modes, it MAY use the
"pages-per-minute" value for this attribute that corresponds to the
mode that produces the highest number.
Printers that are black-and-white only MUST NOT support this
attribute. If this attribute is present, then the "color-supported"
Printer Description attribute MUST be present and have a 'true'
value.
The values of the "pages-per-minute" and "pages-per-minute-color"
attributes returned by the Get-Printer-Attributes operation MAY be
affected by the "document-format" attribute supplied by the Client in
the Get-Printer-Attributes request. In other words, the
implementation MAY have different speeds, depending on the Document
format being processed. See Section 4.2.5.1 ("Get-Printer-Attributes
Request").
6. Conformance
This section describes conformance issues and requirements. This
document introduces model entities such as objects, operations,
attributes, attribute syntaxes, and attribute values. The following
sections describe the conformance requirements that apply to these
model entities.
6.1. Client Conformance Requirements
This section describes the conformance requirements for a Client (see
Section 3.1), whether it be:
1. contained within software controlled by an End User, e.g.,
activated by the "Print" menu item in an application that sends
IPP requests, or
2. the print server component that sends IPP requests to either an
Output Device or another "downstream" print server.
A conforming Client supports all REQUIRED operations as defined in
this document. For each attribute included in an operation request,
a conforming Client MUST supply a value whose type and value syntax
conforms to the requirements specified in Sections 4 and 5 of this
document. A conforming Client MAY supply any Standards Track
extensions and/or vendor extensions in an operation request, as long
as the extensions meet the requirements in Section 7.
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While this document does not define conformance requirements for the
user interfaces provided by IPP Clients or their applications, best
practices for user interfaces are defined in [PWG5100.19].
A Client MUST be able to accept any of the attribute syntaxes defined
in Section 5.1, including their full range, that can be returned to
it in a response from a Printer. In particular, for each attribute
that the Client supports whose attribute syntax is 'text', the Client
MUST accept and process both the 'textWithoutLanguage' and
'textWithLanguage' forms. Similarly, for each attribute that the
Client supports whose attribute syntax is 'name', the Client MUST
accept and process both the 'nameWithoutLanguage' and
'nameWithLanguage' forms. For presentation purposes, truncation of
long attribute values is not recommended. A recommended approach
would be for the Client implementation to allow the user to scroll
through long attribute values.
A response MAY contain attribute groups, attributes, attribute
syntaxes, values, and status-code values that the Client does not
expect. Therefore, a Client implementation MUST gracefully handle
such responses and not refuse to interoperate with a conforming
Printer that is returning Standards Track extensions or vendor
extensions, including attribute groups, attributes, attribute
syntaxes, attribute values, status-code values, and out-of-band
attribute values that conform to Section 7. Clients can choose to
ignore any parameters, attribute groups, attributes, attribute
syntaxes, or values that they do not understand.
While a Client is sending data to a Printer, it SHOULD do its best to
prevent a channel from being closed by a lower layer when the channel
is blocked (i.e., flow-controlled off) for whatever reason, e.g.,
'out of paper' or 'Job ahead hasn't freed up enough memory'.
However, the layer that launched the print submission (e.g., an
End User) MAY close the channel in order to cancel the Job. When a
Client closes a channel, a Printer MAY print all or part of the
received portion of the Document. See the Encoding and Transport
document [RFC8010] for more details.
A Client MUST support Client Authentication as defined in [RFC8010].
A Client SHOULD support Operation Privacy and Server Authentication
as defined in [RFC8010]. See also Section 9 of this document.
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6.2. IPP Object Conformance Requirements
This section specifies the conformance requirements for conforming
implementations of IPP objects (see Section 3). These requirements
apply to an IPP object whether it is:
1) an (embedded) device component that accepts IPP requests and
controls the device, or
2) a component of a print server that accepts IPP requests (where
the print server controls one or more networked devices using IPP
or other protocols).
6.2.1. Objects
Conforming implementations MUST implement all of the model objects as
defined in this document in the indicated sections:
Section 3.1 - Printer Object
Section 3.2 - Job Object
6.2.2. Operations
Conforming IPP object implementations MUST implement all of the
REQUIRED model operations, including REQUIRED responses, as defined
in this document in the indicated sections. Table 20 lists the
operations for a Printer, while Table 21 lists the operations for
a Job.
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+----------------------------------------+-------------+
| Operation | Conformance |
+----------------------------------------+-------------+
| Print-Job (Section 4.2.1) | REQUIRED |
+----------------------------------------+-------------+
| Print-URI (Section 4.2.2) | OPTIONAL |
+----------------------------------------+-------------+
| Validate-Job (Section 4.2.3) | REQUIRED |
+----------------------------------------+-------------+
| Create-Job (Section 4.2.4) | RECOMMENDED |
+----------------------------------------+-------------+
| Get-Printer-Attributes (Section 4.2.5) | REQUIRED |
+----------------------------------------+-------------+
| Get-Jobs (Section 4.2.6) | REQUIRED |
+----------------------------------------+-------------+
| Pause-Printer (Section 4.2.7) | OPTIONAL |
+----------------------------------------+-------------+
| Resume-Printer (Section 4.2.8) | OPTIONAL |
+----------------------------------------+-------------+
| Purge-Jobs (Section 4.2.9) | SHOULD NOT |
+----------------------------------------+-------------+
Table 20: Conformance Requirements for Printer Operations
+------------------------------------+-------------+
| Operation | Conformance |
+------------------------------------+-------------+
| Send-Document (Section 4.3.1) | RECOMMENDED |
+------------------------------------+-------------+
| Send-URI (Section 4.3.2) | RECOMMENDED |
+------------------------------------+-------------+
| Cancel-Job (Section 4.3.3) | REQUIRED |
+------------------------------------+-------------+
| Get-Job-Attributes (Section 4.3.4) | REQUIRED |
+------------------------------------+-------------+
| Hold-Job (Section 4.3.5) | OPTIONAL |
+------------------------------------+-------------+
| Release-Job (Section 4.3.6) | OPTIONAL |
+------------------------------------+-------------+
| Restart-Job (Section 4.3.7) | SHOULD NOT |
+------------------------------------+-------------+
Table 21: Conformance Requirements for Job Operations
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Conforming IPP objects MUST support all REQUIRED operation attributes
and all values of such attributes if so indicated in the description.
Conforming IPP objects MUST ignore all unsupported or unknown
operation attributes or Operation Attributes groups received in a
request but MUST reject a request that contains a supported operation
attribute that contains an unsupported value.
Conforming IPP objects MAY return operation responses that contain
attribute groups, attribute names, attribute syntaxes, attribute
values, and status-code values that are extensions to this
specification. The additional attribute groups MAY occur in any
order.
The following section on object attributes specifies the support
required for object attributes.
6.2.3. IPP Object Attributes
Conforming IPP objects MUST support all of the REQUIRED object
attributes, as defined in this document in the indicated sections.
If an object supports an attribute, it MUST support only those values
specified in this document or through the extension mechanism
described in Section 6.2.5. It MAY support any non-empty subset of
these values. That is, it MUST support at least one of the specified
values and at most all of them.
6.2.4. Versions
IPP/1.1 Clients MUST meet the conformance requirements for Clients
specified in this document and [RFC8010]. IPP/1.1 Clients MUST be
capable of sending requests containing a "version-number" parameter
with a value of '1.1'.
IPP/1.1 Printer and Job objects MUST meet the conformance
requirements for IPP objects specified in this document and
[RFC8010]. IPP/1.1 objects MUST accept requests containing a
"version-number" parameter with a '1.1' value or reject the request
if the operation is not supported.
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It is beyond the scope of this specification to mandate conformance
with other IPP versions. However, IPP was deliberately designed to
make supporting different versions easy. IPP/1.1 Printer
implementations MUST:
o decode and process any well-formed IPP/1.1 request, and
o respond appropriately with a response containing the same
"version-number" parameter value used by the Client in the
request.
IPP/1.1 Client implementations MUST:
o decode and process any well-formed IPP/1.1 response.
IPP Clients SHOULD try supplying alternate version numbers if they
receive a 'server-error-version-not-supported' error in a response.
6.2.5. Extensions
A conforming IPP object MAY support Standards Track extensions and
vendor extensions, as long as the extensions meet the requirements
specified in Section 7.
For each attribute included in an operation response, a conforming
IPP object MUST return a value whose type and value syntax conforms
to the requirements specified in Sections 4 and 5 of this document.
6.2.6. Attribute Syntaxes
An IPP object MUST be able to accept any of the attribute syntaxes
defined in Section 5.1, including their full range, in any operation
in which a Client can supply attributes or the Administrator can
configure attributes (by means outside the scope of this IPP/1.1
document). In particular, for each attribute that the IPP object
supports whose attribute syntax is 'text', the IPP object MUST accept
and process both the 'textWithoutLanguage' and 'textWithLanguage'
forms. Similarly, for each attribute that the IPP object supports
whose attribute syntax is 'name', the IPP object MUST accept and
process both the 'nameWithoutLanguage' and 'nameWithLanguage' forms.
Furthermore, an IPP object MUST return attributes to the Client in
operation responses that conform to the syntaxes specified in
Section 5.1, including their full range if supplied previously by a
Client.
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6.2.7. Security
An IPP Printer implementation SHOULD contain support for Client
Authentication as defined in the IPP/1.1 Encoding and Transport
document [RFC8010]. A Printer implementation MAY allow an
Administrator to configure the Printer so that all, some, or none of
the users are authenticated. See also Section 9 of this document.
An IPP Printer implementation SHOULD contain support for Operation
Privacy and Server Authentication as defined in [RFC8010]. A Printer
implementation MAY allow an Administrator to configure the degree of
support for Operation Privacy and Server Authentication. See also
Section 9 of this document.
Security MUST NOT be compromised when a Client supplies a lower
"version-number" parameter in a request. For example, if a Printer
conforming to IPP/1.1 accepts version '1.0' requests and is
configured to enforce Digest Authentication, it MUST do the same for
a version '1.0' request.
6.3. Charset and Natural Language Requirements
All Clients and IPP objects MUST support the 'utf-8' charset as
defined in Section 5.1.8.
IPP objects MUST be able to accept any Client request that correctly
uses the "attributes-natural-language" operation attribute or the
Natural Language Override mechanism on any individual attribute
whether or not the natural language is supported by the IPP object.
If an IPP object supports a natural language, then it MUST be able to
translate (perhaps by table lookup) all generated 'text' or 'name'
attribute values into one of the supported languages (see
Section 4.1.4).
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7. IANA Considerations
This section describes the procedures for defining Standards Track
and vendor extensions to this document. This affects the following
subregistries of the IANA IPP registry:
1. Objects
2. Attributes
3. Keyword Attribute Values
4. Enum Attribute Values
5. Attribute Group Tags
6. Out-of-Band Attribute Value Tags
7. Attribute Syntaxes
8. Operations
9. Status-Code Values
Extensions registered for use with IPP are OPTIONAL for Client and
IPP object conformance to the IPP/1.1 Model and Semantics document
(this document).
These extension procedures are aligned with the guidelines as set
forth in "Guidelines for Writing an IANA Considerations Section in
RFCs" [RFC5226]. Appendix A describes how to propose new
registrations for consideration. IANA will reject registration
proposals that leave out required information or do not follow the
appropriate format described in Appendix A. The IPP/1.1 Model and
Semantics document can also be extended by an appropriate
Standards Track document that specifies any of the above extensions.
The IANA policy (using terms defined in [RFC5226]) for all extensions
is Specification Required, Expert Review, or First Come First Served
as documented in the following subsections. Registrations submitted
to IANA are forwarded to the IPP Designated Expert(s) who reviews the
proposal on a mailing list that the Designated Expert(s) keeps for
this purpose. Initially, that list is the mailing list used by the
PWG IPP WG:
ipp@pwg.org
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The IPP Designated Expert(s) is appointed by the IESG Area Director
responsible for IPP, according to [RFC5226].
In addition, the IANA-PRINTER-MIB [RFC3805] has been updated to
reference this document; the current version is available from
<http://www.iana.org>.
7.1. Object Extensions
The IANA policy (using terms defined in [RFC5226]) for object
extensions was formerly Expert Review; this document changes the
policy to Specification Required.
7.2. Attribute Extensibility
Since attribute names are type2 keywords (see Section 5.1.4), the
IANA policy (using terms defined in [RFC5226]) for attribute
extensions is Expert Review.
For vendor attribute extensions, implementors SHOULD use keywords
with a suitable distinguishing prefix such as 'smiNNN-' where NNN is
an SMI Private Enterprise Number (PEN) [IANA-PEN]. For example, if
the company Example Corp. had obtained the SMI PEN 32473, then a
vendor attribute 'foo' would be 'smi32473-foo'.
Note: Prior versions of this document recommended using a fully
qualified domain name [RFC1035] as the prefix (e.g.,
'example.com-foo'), and many IPP implementations have also used
reversed domain names (e.g., 'com.example-foo'). Domain names
have proven problematic due to the length of some domain names,
parallel use of country-specific domain names (e.g.,
'example.co.jp-foo'), and changes in ownership of domain names.
If a new Printer attribute is defined and its values can be affected
by a specific Document format, its specification needs to contain the
following sentence:
"The value of this attribute returned in a Get-Printer-Attributes
response MAY depend on the "document-format" attribute supplied
(see Section 4.2.5.1) of the IPP/1.1 Model and Semantics
document."
If the specification does not, then its value in the
Get-Printer-Attributes response MUST NOT depend on the
"document-format" attribute supplied in the request.
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When a new Job Template attribute is registered, the value of the
Printer attributes MAY vary with "document-format" supplied in the
request without the specification having to indicate so.
7.3. Keyword Extensibility
The IANA policy (using terms defined in [RFC5226]) for type1 keyword
extensions is Specification Required. The IANA policy for type2
keyword extensions is Expert Review. The IANA policy for vendor
keyword extensions is First Come First Served. Only attributes using
the type1 and type2 keyword syntax can be registered in the IANA IPP
registry.
Note: The type1 or type2 prefix on the basic attribute syntax is
provided only to communicate the IANA policy required for
registration and is not represented in IPP messages. Both type1
and type2 'keyword' values are represented using the same
'keyword' value tag.
For type1 and type2 keywords, the proposer includes the name of the
keyword in the registration proposal, and the name is part of the
technical review.
For vendor keyword extensions, implementors SHOULD either:
a. follow attribute-specific guidance such as the guidance defined
in [PWG5101.1], or
b. use keywords with a suitable distinguishing prefix, such as
'smiNNN-' where NNN is an SMI Private Enterprise Number (PEN)
[IANA-PEN].
For example, if the company Example Corp. had obtained the
SMI PEN 32473, then a vendor keyword 'foo' would be 'smi32473-foo'.
Note: Prior versions of this document recommended using a fully
qualified domain name [RFC1035] as the prefix (e.g.,
'example.com-foo'), and many IPP implementations have also used
reversed domain names (e.g., 'com.example-foo'). Domain names
have proven problematic due to the length of some domain names,
parallel use of country-specific domain names (e.g.,
'example.co.jp-foo'), and changes in ownership of domain names.
When a type2 keyword extension is approved, the IPP Designated
Expert(s) becomes the point of contact for any future maintenance
that might be required for that registration.
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7.4. Enum Extensibility
The IANA policy (using terms defined in [RFC5226]) for type1 enum
extensions is Specification Required. The IANA policy for type2 enum
extensions is Expert Review. The IANA policy for vendor enum
extensions is First Come First Served. Only attributes using the
type1 and type2 enum syntax can be registered in the IANA IPP
registry.
Note: The type1 or type2 prefix on the basic attribute syntax is
provided only to communicate the IANA policy required for
registration and is not represented in IPP messages. Both type1
and type2 enum values are represented using the same enum
value tag.
For vendor enum extensions, implementors MUST use values in the
reserved integer range, which is 0x40000000 to 0x7fffffff.
Implementors SHOULD consult with the IPP Designated Expert(s) to
reserve vendor extension value(s) for their usage.
When a type1 or type2 enum extension is approved, the IPP Designated
Expert(s), in consultation with IANA, assigns the next available enum
number for each enum value.
When a type2 enum extension is approved, the IPP Designated Expert(s)
becomes the point of contact for any future maintenance that might be
required for that registration.
7.5. Attribute Group Extensibility
The IANA policy (using terms defined in [RFC5226]) for attribute
group extensions was formerly Expert Review; this document changes
the policy to Specification Required.
For attribute groups, the IPP Designated Expert(s), in consultation
with IANA, assigns the next attribute group tag code in the
appropriate range as specified in [RFC8010].
7.6. Out-of-Band Attribute Value Extensibility
The IANA policy (using terms defined in [RFC5226]) for out-of-band
attribute value extensions was formerly Expert Review; this document
changes the policy to Specification Required.
For out-of-band attribute value tags, the IPP Designated Expert(s),
in consultation with IANA, assigns the next out-of-band attribute
value tag code in the appropriate range as specified in [RFC8010].
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7.7. Attribute Syntax Extensibility
The IANA policy (using terms defined in [RFC5226]) for attribute
syntax extensions was formerly Expert Review; this document changes
the policy to Specification Required. The IANA policy for vendor
attribute syntax extensions (tags 0x40000000 to 0x7fffffff) is First
Come First Served. Only attribute syntaxes in the range of
0x00000000 to 0x3fffffff can be registered in the IANA IPP registry.
For vendor attribute syntax extensions, implementors MUST use values
in the reserved integer range, which is 0x40000000 to 0x7fffffff.
Implementors SHOULD consult with the IPP Designated Expert(s) to
reserve vendor extension value(s) for their usage.
For registered attribute syntaxes, the IPP Designated Expert(s), in
consultation with IANA, assigns the next attribute syntax tag in the
appropriate range as specified in [RFC8010].
7.8. Operation Extensibility
The IANA policy (using terms defined in [RFC5226]) for operation
extensions is Expert Review. The IANA policy for vendor operation
extensions (values 0x4000 to 0x7fff) is First Come First Served.
Only operation codes in the range of 0x0000 to 0x3fff can be
registered in the IANA IPP registry.
For vendor operation extensions, implementors MUST use values in the
reserved integer range, which is 0x4000 to 0x7fff. Implementors
SHOULD consult with the IPP Designated Expert(s) to reserve vendor
extension value(s) for their usage.
For registered operation extensions, the IPP Designated Expert(s), in
consultation with IANA, assigns the next "operation-id" code as
specified in Section 5.4.15.
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7.9. Status-Code Extensibility
The IANA policy (using terms defined in [RFC5226]) for status-code
extensions is Expert Review. The IANA policy for vendor status-code
extensions (codes 0x0n80 to 0x0nff, for n = 0 to 5) is First Come
First Served. Only status-code values in the range of 0x0n00 to
0x0n7f can be registered in the IANA IPP registry.
The status-code values are allocated in ranges as specified in
Appendix B for each status-code class:
"informational" - Request received, continuing process
"successful" - The action was successfully received, understood, and
accepted
"redirection" - Further action is taken in order to complete the
request
"client-error" - The request contains bad syntax or cannot be
fulfilled
"server-error" - The IPP object failed to fulfill an apparently valid
request
For vendor operation status-code extensions, implementors MUST use
the top of each range (0x0n80 to 0x0nff) as specified in Appendix B.
Implementors SHOULD consult with the IPP Designated Expert(s) to
reserve vendor extension value(s) for their usage.
For registered operation status-code values, the IPP Designated
Expert(s), in consultation with IANA, assigns the next status-code in
the appropriate class range as specified in Appendix B.
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8. Internationalization Considerations
Some of the attributes have values that are text strings and names
that are intended for human understanding rather than machine
understanding (see the 'text' and 'name' attribute syntaxes in
Sections 5.1.2 and 5.1.3).
In each operation request, the Client
o identifies the charset and natural language of the request that
affects each supplied 'text' and 'name' attribute value, and
o requests the charset and natural language for attributes returned
by the IPP object in operation responses (as described in
Section 4.1.4.1).
In addition, the Client MAY separately and individually identify the
Natural Language Override of a supplied 'text' or 'name' attribute
using the 'textWithLanguage' and 'nameWithLanguage' techniques
described in Sections 5.1.2.2 and 5.1.3.2, respectively.
All IPP objects MUST support the UTF-8 [RFC3629] charset in all
'text' and 'name' attributes supported. If an IPP object supports
more than the UTF-8 charset, the object MUST convert between them in
order to return the requested charset to the Client according to
Section 4.1.4.2. If an IPP object supports more than one natural
language, the object SHOULD return 'text' and 'name' values in the
natural language requested where those values are generated by the
Printer (see Section 4.1.4.1).
For Printers that support multiple charsets and/or multiple natural
languages in 'text' and 'name' attributes, different Jobs might have
been submitted in differing charsets and/or natural languages. All
responses MUST be returned in the charset requested by the Client.
However, the Get-Jobs operation uses the 'textWithLanguage' and
'nameWithLanguage' mechanisms to identify the differing natural
languages with each Job attribute returned.
The Printer also has configured charset and natural language
attributes. The Client can query the Printer to determine the list
of charsets and natural languages supported by the Printer and what
the Printer's configured values are. See the "charset-configured",
"charset-supported", "natural-language-configured", and
"generated-natural-language-supported" Printer Description attributes
for more details.
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The "charset-supported" attribute identifies the supported charsets.
If a charset is supported, the IPP object MUST be capable of
converting to and from that charset into any other supported charset.
In many cases, an IPP object will support only one charset, and it
MUST be the UTF-8 charset.
The "charset-configured" attribute identifies the one supported
charset that is the native charset, given the current configuration
of the IPP object (Administrator defined).
The "generated-natural-language-supported" attribute identifies the
set of supported natural languages for generated messages; it is not
related to the set of natural languages that MUST be accepted for
Client-supplied 'text' and 'name' attributes. For Client-supplied
'text' and 'name' attributes, an IPP object MUST accept ALL supplied
natural languages. For example, if a Client supplies a Job name that
is in 'fr-ca' but the Printer only generates 'en-us', the Printer
object MUST still accept the Job name value.
The "natural-language-configured" attribute identifies the one
supported natural language for generated messages that is the native
natural language, given the current configuration of the IPP object
(Administrator defined).
Attributes of types 'text' and 'name' are populated from different
sources. These attributes can be categorized into the following
groups (depending on the source of the attribute):
1. Some attributes are supplied by the Client (e.g., the
Client-supplied "job-name", "document-name", and
"requesting-user-name" operation attributes along with the
corresponding Job's "job-name" and "job-originating-user-name"
attributes). The IPP object MUST accept these attributes in any
natural language no matter what the set of supported languages
for generated messages.
2. Some attributes are supplied by the Administrator (e.g., the
Printer's "printer-name" and "printer-location" attributes).
These can also be in any natural language. If the natural
language for these attributes is different than what a Client
requests, then they MUST be reported using the Natural Language
Override mechanism.
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3. Some attributes are supplied by the device manufacturer (e.g.,
the Printer's "printer-make-and-model" attribute). These can
also be in any natural language. If the natural language for
these attributes is different than what a Client requests, then
they MUST be reported using the Natural Language Override
mechanism.
4. Some attributes are supplied by the Operator (e.g., the Job's
"job-message-from-operator" attribute). These can also be in any
natural language. If the natural language for these attributes
is different than what a Client requests, then they MUST be
reported using the Natural Language Override mechanism.
5. Some attributes are generated by the IPP object (e.g., the Job's
"job-state-message" attribute, the Printer's
"printer-state-message" attribute, and the "status-message"
operation attribute). These attributes can only be in one of the
"generated-natural-language-supported" natural languages. If a
Client requests some natural language for these attributes other
than one of the supported values, the IPP object SHOULD respond
using the value of the "natural-language-configured" attribute
(using the Natural Language Override mechanism if needed).
The 'text' and 'name' attributes specified in this version of this
document (additional ones will be registered according to the
procedures in Section 7) are shown in Table 22.
+-----------------------------------+-------------------------------+
| Attributes | Source |
+-----------------------------------+-------------------------------+
| Operation Attributes: | |
| | |
| job-name (name) | Client |
| document-name (name) | Client |
| requesting-user-name (name) | Client |
| status-message (text) | Job or Printer |
| detailed-status-message (text) | Job or Printer (note 1) |
| document-access-error (text) | Job or Printer (note 1) |
| | |
| Job Template Attributes: | |
| | |
| job-hold-until (keyword | name) | Client matches Administrator- |
| | configured |
| job-hold-until-default (keyword | | Client matches Administrator- |
| name) | configured |
| job-hold-until-supported (keyword | Client matches Administrator- |
| | name) | configured |
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| job-sheets (keyword | name) | Client matches Administrator- |
| | configured |
| job-sheets-default (keyword | | Client matches Administrator- |
| name) | configured |
| job-sheets-supported (keyword | | Client matches Administrator- |
| name) | configured |
| media (keyword | name) | Client matches Administrator- |
| | configured |
| media-default (keyword | name) | Client matches Administrator- |
| | configured |
| media-supported (keyword | name) | Client matches Administrator- |
| | configured |
| media-ready (keyword | name) | Client matches Administrator- |
| | configured |
| | |
| Job Description Attributes: | |
| | |
| job-name (name) | Client or Printer |
| job-originating-user-name (name) | Printer |
| job-state-message (text) | Job or Printer |
| output-device-assigned | Administrator |
| (name(127)) | |
| job-message-from-operator | Operator |
| (text(127)) | |
| job-detailed-status-messages | Job or Printer (note 1) |
| (1setOf text) | |
| job-document-access-errors | Job or Printer (note 1) |
| (1setOf text) | |
| | |
| Printer Description Attributes: | |
| | |
| printer-name (name(127)) | Administrator |
| printer-location (text(127)) | Administrator |
| printer-info (text(127)) | Administrator |
| printer-make-and-model | Administrator or manufacturer |
| (text(127)) | |
| printer-state-message (text) | Printer |
| printer-message-from-operator | Operator |
| (text(127)) | |
+-----------------------------------+-------------------------------+
Table 22: 'text' and 'name' Attributes
Note 1: Neither the Printer nor the Client localizes these message
attributes, since they are intended for use by the Administrator or
other experienced technical persons.
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9. Security Considerations
It is difficult to anticipate the security risks that might exist in
any given IPP environment. For example, if IPP is used within a
given small business over a private LAN with physical security, the
risks of exposing Document data can be low enough that the business
will choose not to use encryption on that data. However, if the
connection between the Client and the IPP object is over a public
network, the Client can protect the content of the information during
transmission through the network with encryption.
Furthermore, the value of the information being printed can vary from
one IPP environment to the next. Printing payroll checks, for
example, would have a different value than printing public
information from a file. There is also the possibility of denial-of-
service attacks, but denial-of-service attacks against printing
resources are not well understood, and there are no published
precedents regarding this scenario.
Once the authenticated identity of the requester has been supplied to
the IPP object, the object uses that identity to enforce any
authorization policy that might be in place. For example, one site's
policy might be that only the Job owner is allowed to cancel a Job.
The details and mechanisms to set up a particular access control
policy are not part of this document and are typically established
via some other type of administrative or access control framework.
However, there are operation status-code values that allow an IPP
server to return information back to a Client about any potential
access control violations for an IPP object.
During a Job Creation request, the Client's identity is recorded in
the Job object in an implementation-defined attribute. This
information can be used to verify a Client's identity for subsequent
operations on that Job object in order to enforce any access control
policy that might be in effect. See Section 9.3 below for more
details. This and other information stored in the Job object can
also be considered personal or sensitive in nature and can be
filtered out as part of a configured privacy policy (Section 9.4).
Since the security levels or the specific threats that an
Administrator can be concerned with cannot be anticipated, IPP
implementations MUST be capable of operating with different security
mechanisms and security policies as required by the individual
installation. Security policies might vary from very strong to very
weak, or to none at all, and corresponding security mechanisms will
be required.
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9.1. Security Scenarios
The following sections describe specific security attacks for IPP
environments. Where examples are provided, they are illustrative of
the environment and not an exhaustive set.
9.1.1. Client and Server in the Same Security Domain
This environment is typical of internal networks where traditional
office workers print the output of personal productivity applications
on shared workgroup Printers, or where batch applications print their
output on large production Printers. Although the identity of the
user has been authenticated and can be trusted in this environment, a
user might want to protect the content of a Document against such
attacks as eavesdropping, replaying, or tampering by using a secure
transport such as TLS [RFC5246].
9.1.2. Client and Server in Different Security Domains
Examples of this environment include printing a Document created by
the Client on a publicly available Printer, such as at a commercial
print shop, or printing a Document remotely on a business associate's
Printer. This latter operation is functionally equivalent to sending
the Document to the business associate as a facsimile. Printing
sensitive information on a Printer in a different security domain
requires strong security measures. In this environment,
authentication of the Printer is required as well as protection
against unauthorized use of print resources. Since the Document
crosses security domains, protection against eavesdropping and
Document tampering is also required. It will also be important in
this environment to protect Printers against "spamming" and malicious
Document content -- authentication and Document data pre-scanning can
be used to minimize those threats.
9.1.3. Print by Reference
When the Document is not stored on the Client, printing can be done
by reference. That is, the print request can contain a reference, or
pointer, to the Document instead of the actual Document itself -- see
Sections 4.2.2 and 4.3.2. Standard methods currently do not exist
for remote entities to "assume" the credentials of a Client for
forwarding requests to a third party. It is anticipated that print
by reference will be used to access "public" Documents. Note that
sophisticated methods for authenticating "proxies" are beyond the
scope of this IPP/1.1 document. Because Printers typically process
Jobs serially, print by reference is not seen as a serious denial-of-
service threat to the referenced servers.
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9.2. URIs in Operation, Job, and Printer Attributes
The "printer-uri-supported" attribute contains the Printer's URI(s).
Its companion attribute, "uri-security-supported", identifies the
security mechanism used for each URI listed in the
"printer-uri-supported" attribute. For each Printer operation
request, a Client MUST supply only one URI in the "printer-uri"
operation attribute. In other words, even though the Printer
supports more than one URI, the Client only interacts with the
Printer using one of its URIs. This duality is not needed for Job
objects, since Printers will act as the "factory" for Job objects and
a given Printer will, depending on the Printer's security
configuration, generate the correct URI for new Job objects.
9.3. URIs for Each Authentication Mechanism
Each URI has an authentication mechanism associated with it. If the
URI is the "i-th" element of "printer-uri-supported", then the
authentication mechanism is the "i-th" element of
"uri-authentication-supported". For a list of possible
authentication mechanisms, see Section 5.4.2.
The Printer uses an authentication mechanism to determine the name of
the user performing an operation. This user is called the
"authenticated user". The credibility of authentication depends on
the mechanism that the Printer uses to obtain the user's name. When
the authentication mechanism is 'none', all authenticated users are
'anonymous'.
During Job Creation requests, the Printer initializes the value of
the "job-originating-user-name" attribute (see Section 5.3.6) to be
the authenticated user. The authenticated user in this case is
called the "Job owner".
If an implementation can be configured to support more than one
authentication mechanism (see Section 5.4.2), then it MUST implement
rules for determining equality of authenticated user names that have
been authenticated via different authentication mechanisms. One
possible policy is that identical names that are authenticated via
different mechanisms are different. For example, a user can cancel
his Job only if he uses the same authentication mechanism for both
Cancel-Job and Print-Job. Another policy is that identical names
that are authenticated via different mechanisms are the same if the
authentication mechanism for the later operation is not less strong
than the authentication mechanism for the earlier Job Creation
operation. For example, a user can cancel his Job only if he uses
the same or stronger authentication mechanism for Cancel-Job and
Print-Job. With this second policy, a Job submitted via
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'requesting-user-name' authentication could be canceled via 'digest'
authentication. With the first policy, the Job could not be canceled
in this way.
A Client is able to determine the authentication mechanism used to
create a Job. It is the "i-th" value of the Printer's
"uri-authentication-supported" attribute (see Section 5.4.2),
where "i" is the index of the element of the Printer's
"printer-uri-supported" attribute (see Section 5.4.1) equal to the
Job's "job-printer-uri" attribute (see Section 5.3.3).
9.4. Restricted Queries
In many IPP operations, a Client supplies a list of attributes to be
returned in the response. For security reasons, an IPP object can be
configured not to return all attributes (or all values) that a Client
requests. The Job attributes returned MAY depend on whether the
requesting user is the same as the user that submitted the Job. The
IPP object MAY even return none of the requested attributes. In such
cases, the status returned is the same as if the object had returned
all requested attributes. The Client cannot tell by such a response
whether the requested attribute was present or absent in the object.
9.5. Operations Performed by Operators and Administrators
For the three Printer operations Pause-Printer, Resume-Printer, and
Purge-Jobs (see Sections 4.2.7, 4.2.8, and 4.2.9), the requesting
user is intended to be an Operator or Administrator of the Printer
(see Section 1). Otherwise, the IPP Printer MUST reject the
operation and return 'client-error-forbidden',
'client-error-not-authenticated', or 'client-error-not-authorized'
as appropriate. For operations on Jobs, the requesting user is
intended to be the Job owner or can be an Operator or Administrator
of the Printer. The means for authorizing an Operator or
Administrator of the Printer are not specified in this document.
9.6. Queries on Jobs Submitted Using Non-IPP Protocols
If the device that an IPP Printer is representing is able to accept
Jobs using other Job submission protocols in addition to IPP, such an
implementation SHOULD at least allow such "foreign" Jobs to be
queried using Get-Jobs returning "job-id" and "job-uri" as 'unknown'.
Such an implementation MAY support all of the same IPP Job attributes
as for IPP Jobs. The IPP object returns the 'unknown' out-of-band
value for any requested attribute of a foreign Job that is supported
for IPP Jobs but not for foreign Jobs.
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IPP Printers SHOULD also generate "job-id" and "job-uri" values for
such foreign Jobs, if possible, so that they can be targets of other
IPP operations, such as Get-Job-Attributes and Cancel-Job. Such an
implementation also needs to deal with the problem of authentication
of such foreign Jobs. One approach would be to treat all such
foreign Jobs as belonging to users other than the user of the IPP
Client. Another approach would be for the foreign Job to belong to
'anonymous' -- then only authenticated Operators or Administrators of
the IPP Printer could query the foreign Jobs with an IPP request.
Alternatively, if the security policy is to allow users to query
other users' Jobs, then the foreign Jobs would also be visible to an
End User IPP Client using Get-Jobs and Get-Job-Attributes.
10. Changes since RFC 2911
The following changes have been made since RFC 2911:
o Errata ID 364: Fixed range of "redirection" status-code values (to
0x03xx).
o Errata ID 694: Fixed range of vendor status-code values (0x0n80 to
0x0nff).
o Errata ID 3072: Reworded multiple-document-handling definition,
since it also applies to Jobs with a single Document and is the
only interoperable way to request uncollated copies.
o Errata ID 3365: Fixed bad 'nameWithLanguage' maximum length by
referencing the 'nameWithoutLanguage' section (i.e.,
Section 5.1.3.1).
o Errata ID 4173: Fixed range of vendor operation codes (0x4000 to
0x7fff).
o Updated obsoleted RFC references.
o Changed the IPP/1.1 Implementor's Guide reference to RFC 3196.
o Updated Create-Job, Send-Document, and Send-URI to RECOMMENDED.
o Incorporated 'collection' attribute content from RFC 3382.
o Obsoleted all attributes and values defined in RFC 3381, as they
do not interact well with the "finishings" attribute and have
never been widely implemented.
o Deprecated the Purge-Jobs and Restart-Job operations, which
destroy accounting information.
Sweet & McDonald Standards Track [Page 187]
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o Dropped type3 registration procedures.
o Changed the vendor attribute and keyword naming recommendations to
use SMI Private Enterprise Numbers ("smiNNN-foo") instead of
domain names.
o Split READ-ONLY Job Description and Printer Description attributes
into Job Status and Printer Status attributes to match the current
IANA IPP registry organization.
o Referenced all IETF and PWG IPP standards.
o Updated OPTIONAL operations, attributes, and values to RECOMMENDED
for consistency with IPP 2.0, IPP Everywhere, and the IPP
Implementor's Guide v2.0.
o Removed the appendix on media names. Readers are directed to
"PWG Media Standardized Names 2.0 (MSN2)" [PWG5101.1].
11. References
11.1. Normative References
[ASME-Y14.1M]
ASME Y14.1M-2012, "Metric Drawing Sheet Size and Format",
March 2013.
[ISO10175] ISO/IEC 10175, "Information technology -- Text and office
systems -- Document Printing Application (DPA) -- Part 1:
Abstract service definition and procedures",
September 1996.
[ISO10646] ISO/IEC 10646:2014, JTC1/SC2, "Information technology --
Universal Coded Character Set (UCS)", September 2014.
[ISO8859-1]
ISO/IEC 8859-1:1998, "Information technology -- 8-bit
single-byte coded graphic character sets -- Part 1: Latin
alphabet No. 1", April 1998.
[PWG5100.1]
Sweet, M., "IPP Finishings 2.0 (FIN)", December 2014,
<http://ftp.pwg.org/pub/pwg/candidates/
cs-ippfinishings20-20141219-5100.1.pdf>.
Sweet & McDonald Standards Track [Page 188]
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[PWG5100.11]
Hastings, T. and D. Fullman, "Internet Printing Protocol
(IPP): Job and Printer Extensions -- Set 2 (JPS2)",
October 2010, <http://ftp.pwg.org/pub/pwg/candidates/
cs-ippjobprinterext10-20101030-5100.11.pdf>.
[PWG5100.12]
Sweet, M. and I. McDonald, "IPP Version 2.0, 2.1, and
2.2", October 2015, <http://ftp.pwg.org/pub/pwg/standards/
std-ipp20-20151030-5100.12.pdf>.
[PWG5100.13]
Sweet, M., McDonald, I., and P. Zehler, "IPP: Job and
Printer Extensions -- Set 3 (JPS3)", July 2012,
<http://ftp.pwg.org/pub/pwg/candidates/
cs-ippjobprinterext3v10-20120727-5100.13.pdf>.
[PWG5100.14]
Sweet, M., McDonald, I., Mitchell, A., and J. Hutchings,
"IPP Everywhere", January 2013,
<http://ftp.pwg.org/pub/pwg/candidates/
cs-ippeve10-20130128-5100.14.pdf>.
[PWG5100.15]
Sweet, M., "IPP FaxOut Service", June 2014,
<http://ftp.pwg.org/pub/pwg/candidates/
cs-ippfaxout10-20140618-5100.15.pdf>.
[PWG5100.16]
Sweet, M., "IPP Transaction-Based Printing Extensions",
November 2013, <http://ftp.pwg.org/pub/pwg/candidates/
cs-ipptrans10-20131108-5100.16.pdf>.
[PWG5100.17]
Zehler, P. and M. Sweet, "IPP Scan Service (SCAN)",
September 2014, <http://ftp.pwg.org/pub/pwg/candidates/
cs-ippscan10-20140918-5100.17.pdf>.
[PWG5100.18]
Sweet, M. and I. McDonald, "IPP Shared Infrastructure
Extensions (INFRA)", June 2015,
<http://ftp.pwg.org/pub/pwg/candidates/
cs-ippinfra10-20150619-5100.18.pdf>.
[PWG5100.19]
Kennedy, S., "IPP Implementor's Guide v2.0 (IG)",
August 2015, <http://ftp.pwg.org/pub/pwg/candidates/
cs-ippig20-20150821-5100.19.pdf>.
Sweet & McDonald Standards Track [Page 189]
RFC 8011 IPP/1.1: Model and Semantics January 2017
[PWG5100.2]
Hastings, T. and R. Bergman, "Internet Printing Protocol
(IPP): "output-bin" attribute extension", February 2001,
<http://ftp.pwg.org/pub/pwg/candidates/
cs-ippoutputbin10-20010207-5100.2.pdf>.
[PWG5100.3]
Ocke, K. and T. Hastings, "Internet Printing Protocol
(IPP): Production Printing Attributes -- Set1",
February 2001, <http://ftp.pwg.org/pub/pwg/candidates/
cs-ippprodprint10-20010212-5100.3.pdf>.
[PWG5100.5]
Carney, D., Hastings, T., and P. Zehler, "Standard for The
Internet Printing Protocol (IPP): Document Object",
October 2003, <http://ftp.pwg.org/pub/pwg/candidates/
cs-ippdocobject10-20031031-5100.5.pdf>.
[PWG5100.6]
Zehler, P., Herriot, R., and K. Ocke, "Standard for The
Internet Printing Protocol (IPP): Page Overrides",
October 2003, <http://ftp.pwg.org/pub/pwg/candidates/
cs-ipppageoverride10-20031031-5100.6.pdf>.
[PWG5100.7]
Hastings, T. and P. Zehler, "Standard for The Internet
Printing Protocol (IPP): Job Extensions", October 2003,
<http://ftp.pwg.org/pub/pwg/candidates/
cs-ippjobext10-20031031-5100.7.pdf>.
[PWG5100.8]
Carney, D. and H. Lewis, "Standard for Internet Printing
Protocol (IPP): "-actual" attributes", March 2003,
<http://ftp.pwg.org/pub/pwg/candidates/
cs-ippactuals10-20030313-5100.8.pdf>.
[PWG5100.9]
McDonald, I. and C. Whittle, "Internet Printing Protocol
(IPP): Printer State Extensions v1.0", July 2009,
<http://ftp.pwg.org/pub/pwg/candidates/
cs-ippstate10-20090731-5100.9.pdf>.
[PWG5101.1]
Sweet, M., Bergman, R., and T. Hastings, "PWG Media
Standardized Names 2.0 (MSN2)", March 2013,
<http://ftp.pwg.org/pub/pwg/candidates/
cs-pwgmsn20-20130328-5101.1.pdf>.
Sweet & McDonald Standards Track [Page 190]
RFC 8011 IPP/1.1: Model and Semantics January 2017
[RFC20] Cerf, V., "ASCII format for network interchange", STD 80,
RFC 20, DOI 10.17487/RFC20, October 1969,
<http://www.rfc-editor.org/info/rfc20>.
[RFC793] Postel, J., "Transmission Control Protocol", STD 7,
RFC 793, DOI 10.17487/RFC793, September 1981,
<http://www.rfc-editor.org/info/rfc793>.
[RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
November 1987, <http://www.rfc-editor.org/info/rfc1035>.
[RFC1951] Deutsch, P., "DEFLATE Compressed Data Format Specification
version 1.3", RFC 1951, DOI 10.17487/RFC1951, May 1996,
<http://www.rfc-editor.org/info/rfc1951>.
[RFC1952] Deutsch, P., "GZIP file format specification version 4.3",
RFC 1952, DOI 10.17487/RFC1952, May 1996,
<http://www.rfc-editor.org/info/rfc1952>.
[RFC1977] Schryver, V., "PPP BSD Compression Protocol", RFC 1977,
DOI 10.17487/RFC1977, August 1996,
<http://www.rfc-editor.org/info/rfc1977>.
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046,
DOI 10.17487/RFC2046, November 1996,
<http://www.rfc-editor.org/info/rfc2046>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818,
DOI 10.17487/RFC2818, May 2000,
<http://www.rfc-editor.org/info/rfc2818>.
[RFC3196] Hastings, T., Manros, C., Zehler, P., Kugler, C., and H.
Holst, "Internet Printing Protocol/1.1: Implementor's
Guide", RFC 3196, DOI 10.17487/RFC3196, November 2001,
<http://www.rfc-editor.org/info/rfc3196>.
[RFC3380] Hastings, T., Herriot, R., Kugler, C., and H. Lewis,
"Internet Printing Protocol (IPP): Job and Printer Set
Operations", RFC 3380, DOI 10.17487/RFC3380,
September 2002, <http://www.rfc-editor.org/info/rfc3380>.
Sweet & McDonald Standards Track [Page 191]
RFC 8011 IPP/1.1: Model and Semantics January 2017
[RFC3510] Herriot, R. and I. McDonald, "Internet Printing
Protocol/1.1: IPP URL Scheme", RFC 3510,
DOI 10.17487/RFC3510, April 2003,
<http://www.rfc-editor.org/info/rfc3510>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of
ISO 10646", STD 63, RFC 3629, DOI 10.17487/RFC3629,
November 2003, <http://www.rfc-editor.org/info/rfc3629>.
[RFC3805] Bergman, R., Lewis, H., and I. McDonald, "Printer MIB v2",
RFC 3805, DOI 10.17487/RFC3805, June 2004,
<http://www.rfc-editor.org/info/rfc3805>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<http://www.rfc-editor.org/info/rfc3986>.
[RFC3995] Herriot, R. and T. Hastings, "Internet Printing Protocol
(IPP): Event Notifications and Subscriptions", RFC 3995,
DOI 10.17487/RFC3995, March 2005,
<http://www.rfc-editor.org/info/rfc3995>.
[RFC3996] Herriot, R., Hastings, T., and H. Lewis, "Internet
Printing Protocol (IPP): The 'ippget' Delivery Method for
Event Notifications", RFC 3996, DOI 10.17487/RFC3996,
March 2005, <http://www.rfc-editor.org/info/rfc3996>.
[RFC3998] Kugler, C., Lewis, H., and T. Hastings, Ed., "Internet
Printing Protocol (IPP): Job and Printer Administrative
Operations", RFC 3998, DOI 10.17487/RFC3998, March 2005,
<http://www.rfc-editor.org/info/rfc3998>.
[RFC5051] Crispin, M., "i;unicode-casemap - Simple Unicode Collation
Algorithm", RFC 5051, DOI 10.17487/RFC5051, October 2007,
<http://www.rfc-editor.org/info/rfc5051>.
[RFC5234] Crocker, D., Ed., and P. Overell, "Augmented BNF for
Syntax Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
<http://www.rfc-editor.org/info/rfc5234>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
<http://www.rfc-editor.org/info/rfc5246>.
Sweet & McDonald Standards Track [Page 192]
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[RFC5646] Phillips, A., Ed., and M. Davis, Ed., "Tags for
Identifying Languages", BCP 47, RFC 5646,
DOI 10.17487/RFC5646, September 2009,
<http://www.rfc-editor.org/info/rfc5646>.
[RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type
Specifications and Registration Procedures", BCP 13,
RFC 6838, DOI 10.17487/RFC6838, January 2013,
<http://www.rfc-editor.org/info/rfc6838>.
[RFC7230] Fielding, R., Ed., and J. Reschke, Ed., "Hypertext
Transfer Protocol (HTTP/1.1): Message Syntax and Routing",
RFC 7230, DOI 10.17487/RFC7230, June 2014,
<http://www.rfc-editor.org/info/rfc7230>.
[RFC7472] McDonald, I. and M. Sweet, "Internet Printing Protocol
(IPP) over HTTPS Transport Binding and the 'ipps' URI
Scheme", RFC 7472, DOI 10.17487/RFC7472, March 2015,
<http://www.rfc-editor.org/info/rfc7472>.
[RFC7612] Fleming, P. and I. McDonald, "Lightweight Directory Access
Protocol (LDAP): Schema for Printer Services", RFC 7612,
DOI 10.17487/RFC7612, June 2015,
<http://www.rfc-editor.org/info/rfc7612>.
[RFC7616] Shekh-Yusef, R., Ed., Ahrens, D., and S. Bremer, "HTTP
Digest Access Authentication", RFC 7616,
DOI 10.17487/RFC7616, September 2015,
<http://www.rfc-editor.org/info/rfc7616>.
[RFC7617] Reschke, J., "The 'Basic' HTTP Authentication Scheme",
RFC 7617, DOI 10.17487/RFC7617, September 2015,
<http://www.rfc-editor.org/info/rfc7617>.
[RFC8010] Sweet, M. and I. McDonald, "Internet Printing
Protocol/1.1: Encoding and Transport", RFC 8010,
DOI 10.17487/RFC8010, January 2017,
<http://www.rfc-editor.org/info/rfc8010>.
Sweet & McDonald Standards Track [Page 193]
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11.2. Informative References
[HTPP] Barnett, J., Carter, K., and R. deBry, "Internet Print
Protocol Proposal: HTPP -- Hypertext Print Protocol
(HTPP/1.0 Initial Draft)", October 1996,
<ftp://ftp.pwg.org/pub/pwg/ipp/historic/htpp/
overview.ps.gz>.
[IANA-CS] IANA, "Registry of Coded Character Sets",
<http://www.iana.org/assignments/character-sets/>.
[IANA-MT] IANA, "Media Types",
<http://www.iana.org/assignments/media-types/>.
[IANA-PEN]
IANA, "Private Enterprise Numbers",
<http://www.iana.org/assignments/enterprise-numbers/>.
[ISO32000] "Document management -- Portable document format --
Part 1: PDF 1.7", July 2008, <http://www.adobe.com/
devnet/acrobat/pdfs/PDF32000_2008.pdf>.
[LDPA] Isaacson, S., Taylor, D., MacKay, M., Zehler, P.,
Hastings, T., and C. Manros, "LDPA - Lightweight Document
Printing Application", Proposed Internet-Draft,
October 1996, <ftp://ftp.pwg.org/pub/pwg/ipp/
historic/ldpa/ldpa8.pdf.gz>.
[P1387.4] Kirk, M., "POSIX Systems Administration - Part 4: Printing
Interfaces, POSIX 1387.4 D8", 1998.
[PSIS] Herriot, R., Ed., "X/Open: A Printing System
Interoperability Specification (PSIS)", August 1995.
[PWG-IPP-WG]
IEEE-ISTO Printer Working Group, "Internet Printing
Protocol Workgroup", <http://www.pwg.org/ipp>.
[RFC959] Postel, J. and J. Reynolds, "File Transfer Protocol",
STD 9, RFC 959, DOI 10.17487/RFC959, October 1985,
<http://www.rfc-editor.org/info/rfc959>.
[RFC1179] McLaughlin, L., "Line printer daemon protocol", RFC 1179,
DOI 10.17487/RFC1179, August 1990,
<http://www.rfc-editor.org/info/rfc1179>.
Sweet & McDonald Standards Track [Page 194]
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[RFC1738] Berners-Lee, T., Masinter, L., and M. McCahill, "Uniform
Resource Locators (URL)", RFC 1738, DOI 10.17487/RFC1738,
December 1994, <http://www.rfc-editor.org/info/rfc1738>.
[RFC2565] Herriot, R., Ed., Butler, S., Moore, P., and R. Turner,
"Internet Printing Protocol/1.0: Encoding and Transport",
RFC 2565, DOI 10.17487/RFC2565, April 1999,
<http://www.rfc-editor.org/info/rfc2565>.
[RFC2566] deBry, R., Hastings, T., Herriot, R., Isaacson, S., and P.
Powell, "Internet Printing Protocol/1.0: Model and
Semantics", RFC 2566, DOI 10.17487/RFC2566, April 1999,
<http://www.rfc-editor.org/info/rfc2566>.
[RFC2567] Wright, F., "Design Goals for an Internet Printing
Protocol", RFC 2567, DOI 10.17487/RFC2567, April 1999,
<http://www.rfc-editor.org/info/rfc2567>.
[RFC2568] Zilles, S., "Rationale for the Structure of the Model and
Protocol for the Internet Printing Protocol", RFC 2568,
DOI 10.17487/RFC2568, April 1999,
<http://www.rfc-editor.org/info/rfc2568>.
[RFC2569] Herriot, R., Ed., Hastings, T., Jacobs, N., and J. Martin,
"Mapping between LPD and IPP Protocols", RFC 2569,
DOI 10.17487/RFC2569, April 1999,
<http://www.rfc-editor.org/info/rfc2569>.
[RFC2579] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Textual Conventions for SMIv2",
STD 58, RFC 2579, DOI 10.17487/RFC2579, April 1999,
<http://www.rfc-editor.org/info/rfc2579>.
[RFC2978] Freed, N. and J. Postel, "IANA Charset Registration
Procedures", BCP 19, RFC 2978, DOI 10.17487/RFC2978,
October 2000, <http://www.rfc-editor.org/info/rfc2978>.
[RFC3239] Kugler, C., Lewis, H., and T. Hastings, "Internet Printing
Protocol (IPP): Requirements for Job, Printer, and Device
Administrative Operations", RFC 3239,
DOI 10.17487/RFC3239, February 2002,
<http://www.rfc-editor.org/info/rfc3239>.
[RFC3997] Hastings, T., Ed., deBry, R., and H. Lewis, "Internet
Printing Protocol (IPP): Requirements for IPP
Notifications", RFC 3997, DOI 10.17487/RFC3997,
March 2005, <http://www.rfc-editor.org/info/rfc3997>.
Sweet & McDonald Standards Track [Page 195]
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[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Unique IDentifier (UUID) URN Namespace", RFC 4122,
DOI 10.17487/RFC4122, July 2005,
<http://www.rfc-editor.org/info/rfc4122>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>.
[RFC6068] Duerst, M., Masinter, L., and J. Zawinski, "The 'mailto'
URI Scheme", RFC 6068, DOI 10.17487/RFC6068, October 2010,
<http://www.rfc-editor.org/info/rfc6068>.
[RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre,
"Recommendations for Secure Use of Transport Layer
Security (TLS) and Datagram Transport Layer Security
(DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525,
May 2015, <http://www.rfc-editor.org/info/rfc7525>.
[SWP] Moore, P. and S. Butler, "Simple Web Printing (SWP/1.0)",
May 1997, <ftp://ftp.pwg.org/pub/pwg/ipp/new_PRO/
swp9705.pdf>.
Sweet & McDonald Standards Track [Page 196]
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Appendix A. Formats for IPP Registration Proposals
In order to propose an IPP extension for registration, the proposer
must submit an application to IANA by email to "iana@iana.org" or by
filling out the appropriate form on the IANA web pages
(http://www.iana.org). This section specifies the required
information and the formats for proposing registrations of extensions
to IPP as provided in Section 7 for:
1. attributes
2. type2 'keyword' attribute values
3. type2 'enum' attribute values
4. operations
5. status-code values
A.1. Attribute Registration
Type of registration: attribute
Proposed keyword name of this attribute:
Types of attributes (Document Description, Document Status, Document
Template, Event Notifications, Job Description, Job Status, Job
Template, Operation, Printer Description, Printer Status,
Subscription Description, Subscription Status, Subscription
Template):
Operations to be used if the attribute is an operation attribute:
Object (Document, Job, Printer, Subscription, etc. if bound to an
object):
Attribute syntax(es) (include '1setOf' and range; see Section 5.2):
If attribute syntax is 'keyword' or 'enum', is it type1 or type2?
If this is a Printer attribute, MAY the value returned depend on
"document-format"? (See Section 7.2.)
If this is a Job Template attribute, how does its specification
depend on the value of the "multiple-document-handling" attribute?
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Specification of this attribute (follow the style of Section 5.2):
Name of proposer:
Email address of proposer:
Note: For attributes, the IPP Designated Expert will be the point of
contact and change controller for the approved registration
specification, if any maintenance of the registration specification
is needed.
A.2. type2 'keyword' Attribute Value Registration
Type of registration: type2 keyword attribute value
Name of attribute to which this keyword specification is to be added:
Proposed keyword name of this 'keyword' value:
Specification of this 'keyword' value (follow the style of
Section 5.1.4):
Name of proposer:
Email address of proposer:
Note: For type2 keywords, the Designated Expert will be the point of
contact and change controller for the approved registration
specification, if any maintenance of the registration specification
is needed.
A.3. type2 'enum' Attribute Value Registration
Type of registration: type2 enum attribute value
Name of attribute to which this enum specification is to be added:
Keyword symbolic name of this enum value:
Numeric value (to be assigned by the IPP Designated Expert in
consultation with IANA):
Specification of this enum value (follow the style of Section 5.1.5):
Name of proposer:
Email address of proposer:
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Note: For type2 enums, the Designated Expert will be the point of
contact and change controller for the approved registration
specification, if any maintenance of the registration specification
is needed.
A.4. Operation Registration
Type of registration: operation
Proposed name of this operation:
Numeric "operation-id" value according to Section 5.4.15 (to be
assigned by the IPP Designated Expert in consultation with IANA):
Object Target (Document, Job, Printer, Subscription, etc. that
operation is upon):
Specification of this operation (follow the style of Section 4):
Name of proposer:
Email address of proposer:
Note: For operations, the IPP Designated Expert will be the point of
contact and change controller for the approved registration
specification, if any maintenance of the registration specification
is needed.
A.5. Status-Code Registration
Type of registration: status-code
Keyword symbolic name of this status-code value:
Numeric value (to be assigned by the IPP Designated Expert in
consultation with IANA):
Operations that this status-code can be used with:
Specification of this status-code (follow the style of Appendix B):
Name of proposer:
Email address of proposer:
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Note: For status-code values, the Designated Expert will be the point
of contact and change controller for the approved registration
specification, if any maintenance of the registration specification
is needed.
Appendix B. Status-Code Values and Suggested Status-Code Messages
This section defines status-code enum keywords and values that are
used to provide semantic information on the results of an operation
request. Each operation response MUST include a status-code. The
response MAY also contain a status message that provides a short
textual description of the status. The status-code is intended for
use by automata, and the status message is intended for the human
End User.
The prefix of the status keyword defines the class of response as
follows:
"informational" - Request received, continuing process
"successful" - The action was successfully received, understood, and
accepted
"redirection" - Further action is taken in order to complete the
request
"client-error" - The request contains bad syntax or cannot be
fulfilled
"server-error" - The IPP object failed to fulfill an apparently valid
request
As with type2 enums, IPP status-code values are extensible.
Regardless of whether all status-code values are recognized, IPP
Clients MUST understand the class of any status-code, as indicated by
the prefix, and treat any unrecognized response as being equivalent
to the first status-code of that class, with the exception that an
unrecognized response MUST NOT be cached. For example, if an
unrecognized status-code of 'client-error-xxx-yyy' is received by the
Client, it can safely assume that there was something wrong with its
request and treat the response as if it had received a
'client-error-bad-request' status-code. The name of the enum is the
suggested status message for US English.
See [PWG5100.19] for guidelines on presenting status messages to
End Users.
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The status-code values range from 0x0000 to 0x7fff. The value ranges
for each status-code class are as follows:
"successful" - 0x0000 to 0x00ff
"informational" - 0x0100 to 0x01ff
"redirection" - 0x0300 to 0x03ff
"client-error" - 0x0400 to 0x04ff
"server-error" - 0x0500 to 0x05ff
The top half (128 values) of each range (0x0n80 to 0x0nff, for n = 0
to 5) is reserved for vendor use within each status-code class.
Values 0x0600 to 0x7fff are reserved for future assignment by
Standards Track documents and MUST NOT be used.
B.1. Status-Code Values
Each status-code is described below. Appendix B.2 contains a table
that indicates which status-code values apply to which operations.
The Implementor's Guides [RFC3196] [PWG5100.19] provide guidance for
processing IPP attributes for all operations, including status-code
values.
B.1.1. Informational
This class of status-code values indicates a provisional response and
is to be used for informational purposes only.
There are no values defined in this document for this class of
status-code values.
B.1.2. Successful Status-Code Values
This class of status-code values indicates that the Client's request
was successfully received, understood, and accepted.
B.1.2.1. successful-ok (0x0000)
The request has succeeded, and no request attributes were substituted
or ignored. In the case of a response to a Job Creation request, the
'successful-ok' status-code indicates that the request was
successfully received and validated, and that the Job object has been
created; it does not indicate that the Job has been processed. The
transition of the Job object into the 'completed' state is the only
indicator that the Job has been printed.
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B.1.2.2. successful-ok-ignored-or-substituted-attributes (0x0001)
The request has succeeded, but some supplied (1) attributes were
ignored or (2) unsupported values were substituted with supported
values or were ignored in order to perform the operation without
rejecting it. Unsupported attributes, attribute syntaxes, or values
MUST be returned in the Unsupported Attributes group of the response
for all operations. There is an exception to this rule for the query
operations Get-Printer-Attributes, Get-Jobs, and Get-Job-Attributes
for the "requested-attributes" operation attribute only. When the
supplied values of the "requested-attributes" operation attribute are
requesting attributes that are not supported, the IPP object SHOULD
return the "requested-attributes" operation attribute in the
Unsupported Attributes group of the response (with the unsupported
values only). See Sections 4.1.7 and 4.2.1.2.
B.1.2.3. successful-ok-conflicting-attributes (0x0002)
The request has succeeded, but some supplied attribute values
conflicted with the values of other supplied attributes. Either
(1) these conflicting values were substituted with (supported) values
or (2) the attributes were removed in order to process the Job
without rejecting it. Attributes or values that conflict with other
attributes and have been substituted or ignored MUST be returned in
the Unsupported Attributes group of the response for all operations
as supplied by the Client. See Sections 4.1.7 and 4.2.1.2.
B.1.3. Redirection Status-Code Values
This class of status-code values indicates that further action needs
to be taken to fulfill the request.
There are no values defined in this document for this class of
status-code values.
B.1.4. Client Error Status-Code Values
This class of status-code values is intended for cases in which the
Client seems to have erred. The IPP object SHOULD return a message
containing an explanation of the error situation and whether it is a
temporary or permanent condition.
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B.1.4.1. client-error-bad-request (0x0400)
The request could not be understood by the IPP object due to
malformed syntax (such as the value of a fixed-length attribute whose
length does not match the prescribed length for that attribute -- see
the Implementor's Guides [RFC3196] [PWG5100.19]). The IPP
application SHOULD NOT repeat the request without modifications.
B.1.4.2. client-error-forbidden (0x0401)
The IPP object understood the request but is refusing to fulfill it.
Additional authentication information or authorization credentials
will not help, and the request SHOULD NOT be repeated. This
status-code is commonly used when the IPP object does not wish to
reveal exactly why the request has been refused or when no other
response is applicable.
B.1.4.3. client-error-not-authenticated (0x0402)
The request requires user authentication. The IPP Client can repeat
the request with suitable authentication information. If the request
already included authentication information, then this status-code
indicates that authorization has been refused for those credentials.
If this response contains the same challenge as the prior response
and the user agent has already attempted authentication at least
once, then the response message can contain relevant diagnostic
information. This status-code reveals more information than
'client-error-forbidden'.
B.1.4.4. client-error-not-authorized (0x0403)
The requester is not authorized to perform the request. Additional
authentication information or authorization credentials will not
help, and the request SHOULD NOT be repeated. This status-code is
used when the IPP object wishes to reveal that the authentication
information is understandable; however, the requester is explicitly
not authorized to perform the request. This status-code reveals more
information than 'client-error-forbidden' and
'client-error-not-authenticated'.
B.1.4.5. client-error-not-possible (0x0404)
This status-code is used when the request is for something that
cannot happen. For example, there might be a request to cancel a Job
that has already been canceled or aborted by the system. The IPP
Client SHOULD NOT repeat the request.
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B.1.4.6. client-error-timeout (0x0405)
The Client did not produce a request within the time that the IPP
object was prepared to wait. For example, a Client issued a
Create-Job operation and then, after a long period of time, issued a
Send-Document operation; this error status-code was returned in
response to the Send-Document request (see Section 4.3.1). The IPP
object might have been forced to clean up resources that had been
held for the waiting additional Documents. The IPP object was forced
to close the Job, since the Client took too long. The Client
SHOULD NOT repeat the request without modifications.
B.1.4.7. client-error-not-found (0x0406)
The IPP object has not found anything matching the request URI. No
indication is given of whether the condition is temporary or
permanent. For example, a Client with an old reference to a Job
(a URI) tries to cancel the Job; however, in the meantime the Job
might have been completed and all record of it at the Printer has
been deleted. This status-code, 'client-error-not-found', is
returned indicating that the referenced Job cannot be found. This
error status-code is also used when a Client supplies a URI as a
reference to the Document data in either a Print-URI or Send-URI
operation but the Document cannot be found.
In practice, an IPP application should avoid a "not found" situation
by first querying and presenting a list of valid Printer URIs and Job
URIs to the End User.
B.1.4.8. client-error-gone (0x0407)
The requested object is no longer available, and no forwarding
address is known. This condition should be considered permanent.
Clients with link-editing capabilities should delete references to
the request URI after user approval. If the IPP object does not know
or has no facility to determine whether or not the condition is
permanent, the status-code 'client-error-not-found' should be used
instead.
This response is primarily intended to assist the task of maintenance
by notifying the recipient that the resource is intentionally
unavailable and that the IPP object Administrator desires that remote
links to that resource be removed. It is not necessary to mark all
permanently unavailable resources as "gone" or to keep the mark for
any length of time -- that is left to the discretion of the IPP
object Administrator and/or Printer implementation.
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B.1.4.9. client-error-request-entity-too-large (0x0408)
The IPP object is refusing to process a request because the request
entity is larger than the IPP object is willing or able to process.
An IPP Printer returns this status-code when it limits the size of
Print Jobs and it receives a Print Job that exceeds that limit or
when the attributes are so many that their encoding causes the
request entity to exceed IPP object capacity.
B.1.4.10. client-error-request-value-too-long (0x0409)
The IPP object is refusing to service the request because one or more
of the Client-supplied attributes have a variable-length value that
is longer than the maximum length specified for that attribute. The
IPP object might not have sufficient resources (memory, buffers,
etc.) to process (even temporarily), interpret, and/or ignore a value
larger than the maximum length. Another use of this error code is
when the IPP object supports the processing of a large value that is
less than the maximum length, but during the processing of the
request as a whole, the object can pass the value onto some other
system component that is not able to accept the large value. For
more details, see the Implementor's Guides [RFC3196] [PWG5100.19].
Note: For attribute values that are URIs, this rare condition is only
likely to occur when a Client has improperly submitted a request with
long query information (e.g., an IPP application allows an End User
to enter an invalid URI), when the Client has descended into a URI
"black hole" of redirection (e.g., a redirected URI prefix that
points to a suffix of itself), or when the IPP object is under attack
by a Client attempting to exploit security holes present in some IPP
objects using fixed-length buffers for reading or manipulating the
request URI.
B.1.4.11. client-error-document-format-not-supported (0x040a)
The IPP object is refusing to service the request because the
Document data is in a format, as specified in the "document-format"
operation attribute, that is not supported by the Printer. This
error is returned independent of the Client-supplied
"ipp-attribute-fidelity" attribute. The Printer MUST return this
status-code, even if there are other Job Template attributes that are
not supported as well, since this error is a bigger problem than with
Job Template attributes. See Sections 4.1.6.1, 4.1.7, and 4.2.1.1.
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B.1.4.12. client-error-attributes-or-values-not-supported (0x040b)
In a Job Creation request, if the Printer does not support one or
more attributes, attribute syntaxes, or attribute values supplied in
the request and the Client supplied the "ipp-attribute-fidelity"
operation attribute with the 'true' value, the Printer MUST return
this status-code. The Printer MUST also return in the Unsupported
Attributes group all the attributes and/or values supplied by the
Client that are not supported. See Section 4.1.7. Examples would be
if the request indicates 'iso-a4' media but that media type is not
supported by the Printer, or if the Client supplies a Job Template
attribute and the attribute itself is not even supported by the
Printer. If the "ipp-attribute-fidelity" attribute is 'false', the
Printer MUST ignore or substitute values for unsupported Job Template
attributes and values rather than reject the request and return this
status-code.
For any operation where a Client requests attributes (such as a
Get-Jobs, Get-Printer-Attributes, or Get-Job-Attributes operation),
if the IPP object does not support one or more of the requested
attributes, the IPP object simply ignores the unsupported requested
attributes and processes the request as if they had not been
supplied, rather than returning this status-code. In this case,
the IPP object MUST return the
'successful-ok-ignored-or-substituted-attributes' status-code and
SHOULD return the unsupported attributes as values of the
"requested-attributes" operation attribute in the Unsupported
Attributes group (see Appendix B.1.2.2).
B.1.4.13. client-error-uri-scheme-not-supported (0x040c)
The scheme of the Client-supplied URI in a Print-URI or a Send-URI
operation is not supported. See Sections 4.1.6.1 and 4.1.7.
B.1.4.14. client-error-charset-not-supported (0x040d)
For any operation, if the IPP Printer does not support the charset
supplied by the Client in the "attributes-charset" operation
attribute, the Printer MUST reject the operation and return this
status-code, and any 'text' or 'name' attributes using the 'utf-8'
charset (Section 4.1.4.1). See Sections 4.1.6.1 and 4.1.7.
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B.1.4.15. client-error-conflicting-attributes (0x040e)
The request is rejected because some attribute values conflicted with
the values of other attributes that this document does not permit to
be substituted or ignored. The Printer MUST also return in the
Unsupported Attributes group the conflicting attributes supplied by
the Client. See Sections 4.1.7 and 4.2.1.2.
B.1.4.16. client-error-compression-not-supported (0x040f)
The IPP object is refusing to service the request because the
Document data, as specified in the "compression" operation attribute,
is compressed in a way that is not supported by the Printer. This
error is returned independent of the Client-supplied
"ipp-attribute-fidelity" attribute. The Printer MUST return this
status-code, even if there are other Job Template attributes that are
not supported as well, since this error is a bigger problem than with
Job Template attributes. See Sections 4.1.6.1, 4.1.7, and 4.2.1.1.
B.1.4.17. client-error-compression-error (0x0410)
The IPP object is refusing to service the request because the
Document data cannot be decompressed when using the algorithm
specified by the "compression" operation attribute. This error is
returned independent of the Client-supplied "ipp-attribute-fidelity"
attribute. The Printer MUST return this status-code, even if there
are Job Template attributes that are not supported as well, since
this error is a bigger problem than with Job Template attributes.
See Sections 4.1.7 and 4.2.1.1.
B.1.4.18. client-error-document-format-error (0x0411)
The IPP object is refusing to service the request because the Printer
encountered an error in the Document data while interpreting it.
This error is returned independent of the Client-supplied
"ipp-attribute-fidelity" attribute. The Printer MUST return this
status-code, even if there are Job Template attributes that are not
supported as well, since this error is a bigger problem than with Job
Template attributes. See Sections 4.1.7 and 4.2.1.1.
B.1.4.19. client-error-document-access-error (0x0412)
The IPP object is refusing to service the Print-URI or Send-URI
request because the Printer encountered an access error while
attempting to validate the accessibility of, or access to, the
Document data specified in the "document-uri" operation attribute.
The Printer MAY also return a specific Document access error code
using the "document-access-error" operation attribute (see
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Section 4.1.6.4). This error is returned independent of the
Client-supplied "ipp-attribute-fidelity" attribute. The Printer MUST
return this status-code, even if there are Job Template attributes
that are not supported as well, since this error is a bigger problem
than with Job Template attributes. See Sections 4.1.6.1 and 4.1.7.
B.1.5. Server Error Status-Code Values
This class of status-code values indicates cases in which the IPP
object is aware that it has erred or is incapable of performing the
request. The IPP object SHOULD include a message containing an
explanation of the error situation, and whether it is a temporary or
permanent condition.
B.1.5.1. server-error-internal-error (0x0500)
The IPP object encountered an unexpected condition that prevented it
from fulfilling the request. This error status-code differs from
'server-error-temporary-error' in that it implies a more permanent
type of internal error. It also differs from
'server-error-device-error' in that it implies an unexpected
condition (unlike a paper-jam or out-of-toner problem, which is
undesirable but expected). This error status-code indicates that
intervention by a knowledgeable human is probably required.
B.1.5.2. server-error-operation-not-supported (0x0501)
The IPP object does not support the functionality required to fulfill
the request. This is the appropriate response when the IPP object
does not recognize an operation or is not capable of supporting it.
See Sections 4.1.6.1 and 4.1.7.
B.1.5.3. server-error-service-unavailable (0x0502)
The IPP object is currently unable to handle the request due to
temporary overloading or due to maintenance of the IPP object. The
implication is that this is a temporary condition that will be
alleviated after some delay. If known, the length of the delay can
be indicated in the message. If no delay is given, the IPP
application should handle the response as it would for a
'server-error-temporary-error' response. If the condition is more
permanent, the 'client-error-gone' or 'client-error-not-found' error
status-code could be used.
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B.1.5.4. server-error-version-not-supported (0x0503)
The IPP object does not support or refuses to support the IPP version
that was supplied as the value of the "version-number" operation
parameter in the request. The IPP object is indicating that it is
unable or unwilling to complete the request using the same major and
minor version number as supplied in the request, other than with this
error message. The error response SHOULD contain a "status-message"
attribute (see Section 4.1.6.2) describing why that version is not
supported and what other versions are supported by that IPP object.
See Sections 4.1.6.1, 4.1.7, and 4.1.8.
The error response MUST identify in the "version-number" operation
parameter the closest version number that the IPP object does
support. For example, if a Client supplies version '1.0' and an
IPP/1.1 object supports version '1.0', then it responds with
version '1.0' in all responses to such a request. If the IPP/1.1
object does not support version '1.0', then it should accept the
request and respond with version '1.1' or can reject the request and
respond with this error code and version '1.1'. If a Client supplies
version '1.2', the IPP/1.1 object should accept the request and
return version '1.1' or can reject the request and respond with this
error code and version '1.1'. See Sections 4.1.8 and 5.3.14.
B.1.5.5. server-error-device-error (0x0504)
A Printer error, such as a paper jam, occurs while the IPP object
processes a Print or send operation. The response contains the true
Job status (the values of the "job-state" and "job-state-reasons"
attributes). Additional information can be returned in the OPTIONAL
"job-state-message" attribute value or in the OPTIONAL status message
that describes the error in more detail. This error status-code is
only returned in situations where the Printer is unable to accept the
Job Creation request because of such a device error. For example, if
the Printer is unable to spool and can only accept one Job at a time,
the reason it might reject a Job Creation request is that the Printer
currently has a paper jam. In many cases, however, where the Printer
can accept the request even though the Printer has some error
condition, the 'successful-ok' status-code will be returned. In such
a case, the Client would look at the returned Job object attributes
or later query the Printer to determine its state and state reasons.
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B.1.5.6. server-error-temporary-error (0x0505)
A temporary error such as a buffer-full write error, a memory
overflow (i.e., the Document data exceeds the memory of the Printer),
or a disk-full condition, occurs while the IPP Printer processes an
operation. The Client MAY try the unmodified request again at some
later point in time with an expectation that the temporary internal
error condition has been cleared. Alternatively, as an
implementation option, a Printer MAY delay the response until the
temporary condition is cleared so that no error is returned.
B.1.5.7. server-error-not-accepting-jobs (0x0506)
This is a temporary error indicating that the Printer is not
currently accepting Jobs because the Administrator has set the value
of the Printer's "printer-is-accepting-jobs" attribute to 'false' (by
means outside the scope of this IPP/1.1 document).
B.1.5.8. server-error-busy (0x0507)
This is a temporary error indicating that the Printer is too busy
processing Jobs and/or other requests. The Client SHOULD try the
unmodified request again at some later point in time with an
expectation that the temporary busy condition will have been cleared.
B.1.5.9. server-error-job-canceled (0x0508)
This is an error indicating that the Job has been canceled by an
Operator or the system while the Client was transmitting the data to
the IPP Printer. If a "job-id" attribute and a "job-uri" attribute
had been created, then they are returned in the Print-Job,
Send-Document, or Send-URI response as usual; otherwise, no "job-id"
and "job-uri" attributes are returned in the response.
B.1.5.10. server-error-multiple-document-jobs-not-supported (0x0509)
The IPP object does not support multiple Documents per Job, and a
Client attempted to supply Document data with a second Send-Document
or Send-URI operation.
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B.2. Status-Code Values for IPP Operations
PJ = Print-Job, PU = Print-URI, CJ = Create-Job, SD = Send-Document,
SU = Send-URI, V = Validate-Job, GA = Get-Job-Attributes and
Get-Printer-Attributes, GJ = Get-Jobs, C = Cancel-Job
IPP Operations
IPP Status Keyword PJ PU CJ SD SU V GA GJ C
------------------ -- -- -- -- -- - -- -- -
successful-ok x x x x x x x x x
successful-ok-ignored-or-substituted- x x x x x x x x x
attributes
successful-ok-conflicting-attributes x x x x x x x x x
client-error-bad-request x x x x x x x x x
client-error-forbidden x x x x x x x x x
client-error-not-authenticated x x x x x x x x x
client-error-not-authorized x x x x x x x x x
client-error-not-possible x x x x x x x x x
client-error-timeout x x
client-error-not-found x x x x x x x x x
client-error-gone x x x x x x x x x
client-error-request-entity-too-large x x x x x x x x x
client-error-request-value-too-long x x x x x x x x x
client-error-document-format-not- x x x x x x
supported
client-error-attributes-or-values-not- x x x x x x x x x
supported
client-error-uri-scheme-not-supported x x
client-error-charset-not-supported x x x x x x x x x
client-error-conflicting-attributes x x x x x x x x x
client-error-compression-not-supported x x x x x
client-error-compression-error x x x x
client-error-document-format-error x x x x
client-error-document-access-error x x
server-error-internal-error x x x x x x x x x
server-error-operation-not-supported x x x x
server-error-service-unavailable x x x x x x x x x
server-error-version-not-supported x x x x x x x x x
server-error-device-error x x x x x
server-error-temporary-error x x x x x
server-error-not-accepting-jobs x x x x
server-error-busy x x x x x x x x x
server-error-job-canceled x x x
server-error-multiple-document-jobs- x x
not-supported
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HJ = Hold-Job, RJ = Release-Job, RS = Restart-Job,
PP = Pause-Printer, RP = Resume-Printer, PJ = Purge-Jobs
IPP Operations (cont.)
IPP Status Keyword HJ RJ RS PP RP PJ
------------------ -- -- -- -- -- --
successful-ok x x x x x x
successful-ok-ignored-or-substituted- x x x x x x
attributes
successful-ok-conflicting-attributes x x x x x x
client-error-bad-request x x x x x x
client-error-forbidden x x x x x x
client-error-not-authenticated x x x x x x
client-error-not-authorized x x x x x x
client-error-not-possible x x x x x x
client-error-timeout
client-error-not-found x x x x x x
client-error-gone x x x x x x
client-error-request-entity-too-large x x x x x x
client-error-request-value-too-long x x x x x x
client-error-document-format-not-
supported
client-error-attributes-or-values-not- x x x x x x
supported
client-error-uri-scheme-not-supported
client-error-charset-not-supported x x x x x x
client-error-conflicting-attributes x x x x x x
client-error-compression-not-supported
client-error-compression-error
client-error-document-format-error
client-error-document-access-error
server-error-internal-error x x x x x x
server-error-operation-not-supported x x x x x x
server-error-service-unavailable x x x x x x
server-error-version-not-supported x x x x x x
server-error-device-error
server-error-temporary-error x x x x x x
server-error-not-accepting-jobs
server-error-busy x x x x x x
server-error-job-canceled
server-error-multiple-document-jobs-
not-supported
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Appendix C. Processing IPP Attributes
When submitting a Print Job to a Printer, the IPP Model allows a
Client to supply operation and Job Template attributes along with the
Document data. These Job Template attributes in the Job Creation
request affect the rendering, production, and finishing of the
Documents in the Job. Similar types of instructions can also be
contained in the Document data itself. In addition, the Printer has
a set of attributes that describe what rendering and finishing
processes are supported by that Printer. This model, which allows
for flexibility and power, also introduces the potential that
Client-supplied attributes can conflict with either:
o what the implementation is capable of realizing (i.e., what the
Printer supports), or
o the instructions embedded within the Document data itself.
The following sections describe how these two types of conflicts are
handled in the IPP Model.
C.1. Fidelity
If there is a conflict between what the Client requests and what a
Printer supports, the Client can request one of two possible
conflict-handling mechanisms:
1) either reject the Job, since the Job cannot be processed exactly
as specified, or
2) allow the Printer to make any changes necessary to proceed with
processing the Job the best it can.
In the first case, the Client is indicating the following to the
Printer: "Print the Job exactly as specified with no exceptions, and
if that can't be done, don't even bother printing the Job at all."
In the second case, the Client is indicating the following to the
Printer: "It is more important to make sure the Job is printed rather
than be processed exactly as specified; just make sure the Job is
printed even if some Client-supplied attributes need to be changed or
ignored."
The IPP Model accounts for this situation by introducing an
"ipp-attribute-fidelity" attribute.
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In a Job Creation request, "ipp-attribute-fidelity" is a boolean
operation attribute that MAY be supplied by the Client. The value
'true' indicates that total fidelity to Client-supplied Job Template
attributes and values is required. The Client is requesting that the
Job be printed exactly as specified, and if that is not possible,
then the Job MUST be rejected rather than processed incorrectly. The
value 'false' indicates that a reasonable attempt to print the Job is
acceptable. If a Printer does not support some of the
Client-supplied Job Template attributes or values, the Printer MUST
ignore or replace them with supported values. The Printer can choose
to substitute the default value associated with that attribute or use
some other supported value that is similar to the unsupported
requested value. For example, if a Client supplies a "media" value
of 'na_letter_8.5x11in', the Printer can choose to substitute
'iso_a4_210x297mm' rather than a default value of
'na_personal_3.625x6.5in'. If the Client does not supply the
"ipp-attribute-fidelity" attribute, the Printer assumes a value of
'false'.
Each Printer implementation MUST support both types of "fidelity"
printing (that is, whether the Client supplies a value of 'true' or
'false'):
o If the Client supplies 'false' or does not supply the attribute,
the Printer MUST always accept the request by ignoring unsupported
Job Template attributes and by substituting unsupported values of
supported Job Template attributes with supported values.
o If the Client supplies 'true', the Printer MUST reject the request
if the Client supplies unsupported Job Template attributes.
Since a Client can always query a Printer to find out exactly what is
and is not supported, "ipp-attribute-fidelity" set to 'false' is
useful when:
1) The End User uses a command line interface to request attributes
that might not be supported.
2) In a GUI context, if the End User expects the Job might be moved
to another Printer and prefers a suboptimal result to nothing
at all.
3) The End User just wants something reasonable in lieu of nothing
at all.
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C.2. Page Description Language (PDL) Override
If there is a conflict between the value of an IPP Job Template
attribute and a corresponding instruction in the Document data, the
value of the IPP attribute SHOULD take precedence over the Document
instruction. Consider the case where a previously formatted file of
Document data is sent to an IPP Printer. In this case, if the Client
supplies any attributes at Job submission time, the Client desires
that those attributes override the embedded instructions. Consider
the case where a previously formatted Document has embedded in it
commands to load 'iso-a4' media. However, the Document is passed to
an End User that only has access to a Printer with 'na-letter' media
loaded. That End User most likely wants to submit that Document to
an IPP Printer with the "media" Job Template attribute set to
'na-letter'. Attributes supplied at Job submission time should take
precedence over the embedded PDL instructions. However, until
companies that supply Document data interpreters allow a way for
external IPP attributes to take precedence over embedded Job
production instructions, a Printer might not be able to support the
semantics that IPP attributes override the embedded instructions.
The IPP Model accounts for this situation by introducing a
"pdl-override-supported" attribute that describes the Printer's
capabilities to override instructions embedded in the PDL data
stream. The value of the "pdl-override-supported" attribute is
configured by means outside the scope of this IPP/1.1 document.
This REQUIRED Printer attribute takes on the following values:
o 'attempted': This value indicates that the Printer attempts to
make the IPP attribute values take precedence over embedded
instructions in the Document data; however, there is no guarantee.
o 'not-attempted': This value indicates that the Printer makes no
attempt to make the IPP attribute values take precedence over
embedded instructions in the Document data.
At Job processing time, an implementation that supports the value of
'attempted' might do one of several different actions:
1) Generate an Output-Device-specific command sequence to realize
the feature represented by the IPP attribute value.
2) Parse the Document data itself and replace the conflicting
embedded instruction with a new embedded instruction that matches
the intent of the IPP attribute value.
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3) Indicate to the Printer that external supplied attributes take
precedence over embedded instructions and then pass the external
IPP attribute values to the Document data interpreter.
4) Anything else that allows for the semantics that IPP attributes
override embedded Document data instructions.
Since 'attempted' does not offer any type of guarantee, even though a
given Printer might not do a very "good" job of attempting to ensure
that IPP attributes take a higher precedence over instructions
embedded in the Document data, it would still be a conforming
implementation.
At Job processing time, an implementation that supports the value of
'not-attempted' might do one of the following actions:
1) Simply prepend the Document data with the PDL instruction that
corresponds to the Client-supplied PDL attribute, such that if
the Document data also has the same PDL instruction it will
override what the Printer prepended. In other words, this
implementation is using the same implementation semantics for the
Client-supplied IPP attributes as for the Printer defaults.
2) Parse the Document data and replace the conflicting embedded
instruction with a new embedded instruction that approximates,
but does not match, the semantic intent of the IPP attribute
value.
Note: The "ipp-attribute-fidelity" attribute applies to the Printer's
ability to either accept or reject other unsupported Job Template
attributes. In other words, if "ipp-attribute-fidelity" is set to
'true', a Job is accepted if and only if the Client-supplied Job
Template attributes and values are supported by the Printer. Whether
these attributes actually affect the processing of the Job when the
Document data contains embedded instructions depends on the ability
of the Printer to override the instructions embedded in the Document
data with the semantics of the IPP attributes. If the Document data
attributes can be overridden ("pdl-override-supported" set to
'attempted'), the Printer makes an attempt to use the IPP attributes
when processing the Job. If the Document data attributes cannot be
overridden ("pdl-override-supported" set to 'not-attempted'), the
Printer makes no attempt to override the embedded Document data
instructions with the IPP attributes when processing the Job, and
hence, the IPP attributes can fail to affect the Job processing and
output when the corresponding instruction is embedded in the
Document data.
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C.3. Using Job Template Attributes during Document Processing
The Printer uses some of the Job's Job Template attributes during the
processing of the Document data associated with that Job. These
include, but are not limited to, "orientation-requested",
"number-up", "sides", "media", and "copies". The processing of each
Document in a Job object MUST follow the steps below. These steps
are intended only to identify when and how attributes are to be used
in processing Document data; any alternative steps that accomplish
the same effect can be used to implement this specification document.
1. Using the Client-supplied "document-format" attribute or some
form of Document format detection algorithm (if the value of
"document-format" is not specific enough), determine whether the
Document data has already been formatted for printing. If the
Document data has been formatted, then go to step 2. Otherwise,
the Document data MUST be formatted. The formatting detection
algorithm is implementation defined and is not specified by this
document. The formatting of the Document data uses the
"orientation-requested" attribute to determine how the formatted
print data should be placed on an Input Page; see Section 5.2.10
for details.
2. The Document data is a set of Input Pages in a known media type.
The "page-ranges" attribute is used to select, as specified in
Section 5.2.7, a sub-sequence of the pages in the print-stream
that are to be processed and imaged.
3. The input for this step is a sequence of Input Pages. This step
is controlled by the "number-up" attribute. If the value of
"number-up" is N, then during the processing of the Input Pages
each N Input Pages are positioned, as specified in Section 5.2.9,
to create a single Impression. If a given Document does not have
N more Input Pages, then the completion of the Impression is
controlled by the "multiple-document-handling" attribute as
described in Section 5.2.4; when the value of this attribute is
'single-document' or 'single-document-new-sheet', the Input Pages
of Document data from subsequent Documents are used to complete
the Impression.
The size (scaling), position (translation), and rotation of the Input
Pages on the Impression are implementation defined. Note that during
this process the Input Pages can be rendered to a form suitable for
placing on the Impression; this rendering is controlled by the values
of the "printer-resolution" and "print-quality" attributes as
described in Sections 5.2.12 and 5.2.13. In the case where N = 1,
the Impression is nearly the same as the Input Page; the differences
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would only be in the size, position, and rotation of the Input Page
and/or any decoration, such as a frame for the page, that is added by
the implementation.
1. The collection of Impressions is placed, in sequence, onto sides
of the Media Sheets. This placement is controlled by the "sides"
attribute and the orientation of the Input Page, as described in
Section 5.2.8. The orientation of the Input Pages affects the
orientation of the Impression; for example, if "number-up" equals
2, then, typically, two portrait Input Pages become one landscape
Impression. Note that the placement of Impressions onto Media
Sheets is also controlled by the "multiple-document-handling"
attribute as described in Section 5.2.4.
2. The "copies" and "multiple-document-handling" attributes are used
to determine how many copies of each Media Sheet are printed and
in what order. See Sections 5.2.4 and 5.2.5 for details.
3. When the correct number of copies are created, the Media Sheets
are finished according to the values of the "finishings"
attribute as described in Section 5.2.6. Note that sometimes
finishing processes can require manual intervention to perform
the finishing processes on the copies, especially uncollated
copies. This document allows any or all of the processing steps
to be performed automatically or manually, at the discretion of
the Printer.
Appendix D. Generic Directory Schema
This section defines a generic schema for an entry in a directory
service. Implementations of this schema are defined by "Lightweight
Directory Access Protocol (LDAP): Schema for Printer Services"
[RFC7612] and "IPP Everywhere" [PWG5100.14]. A directory service is
a means by which service users can locate service providers. In IPP
environments, this means that IPP Printers can be registered (either
automatically or with the help of an Administrator) as entries of
type Printer in the directory using an implementation-specific
mechanism such as entry attributes, entry type fields, specific
branches, etc. Directory Clients can search or browse for entries of
type Printer. Clients use the directory service to find entries
based on naming, organizational contexts, or filtered searches on
attribute values of entries. For example, a Client can find all
Printers in the "Local Department" context. Authentication and
authorization are also often part of a directory service so that an
Administrator can place limits on End Users so that they are only
allowed to find entries to which they have certain access rights.
IPP itself does not require any specific directory service protocol
or provider.
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Note: Some directory implementations allow for the notion of
"aliasing". That is, one directory entry object can appear as
multiple directory entry objects with different names for each
object. In each case, each alias refers to the same directory entry
object, which refers to a single IPP Printer.
The generic schema is a subset of IPP Printer Job Template and
Printer Description attributes (Sections 5.2 and 5.4). These
attributes are identified as either RECOMMENDED or OPTIONAL for the
directory entry itself. This conformance labeling is NOT the same
conformance labeling applied to the attributes of IPP Printer
objects. The conformance labeling in this appendix is intended to
apply to directory templates and to IPP Printer implementations that
subscribe by adding one or more entries to a directory. RECOMMENDED
attributes SHOULD be associated with each directory entry. OPTIONAL
attributes MAY be associated with the directory entry (if known or
supported). In addition, all directory entry attributes SHOULD
reflect the current attribute values for the corresponding Printer.
As much as possible, the names of attributes in directory schema and
entries SHOULD be the same as the IPP Printer attribute names as
shown.
In order to bridge between the directory service and the IPP Printer,
one of the RECOMMENDED directory entry attributes is the Printer's
"printer-uri-supported" attribute. The directory Client queries the
"printer-uri-supported" attribute (or its equivalent) in the
directory entry, and then the IPP Client addresses the IPP Printer
using one of its URIs. The "uri-security-supported" attribute
identifies the protocol (if any) used to secure a channel.
The attributes in Table 23 define the generic schema for directory
entries of type Printer.
+------------------------------------+-------------+----------------+
| Attribute | Conformance | Section |
+------------------------------------+-------------+----------------+
| charset-supported | OPTIONAL | Section 5.4.18 |
+------------------------------------+-------------+----------------+
| color-supported | RECOMMENDED | Section 5.4.26 |
+------------------------------------+-------------+----------------+
| compression-supported | RECOMMENDED | Section 5.4.32 |
+------------------------------------+-------------+----------------+
| document-format-supported | RECOMMENDED | Section 5.4.22 |
+------------------------------------+-------------+----------------+
| finishings-supported | OPTIONAL | Section 5.2.6 |
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+------------------------------------+-------------+----------------+
| generated-natural-language- | OPTIONAL | Section 5.4.20 |
| supported | | |
+------------------------------------+-------------+----------------+
| ipp-versions-supported | RECOMMENDED | Section 5.4.14 |
+------------------------------------+-------------+----------------+
| media-supported | RECOMMENDED | Section 5.2.11 |
+------------------------------------+-------------+----------------+
| multiple-document-jobs-supported | OPTIONAL | Section 5.4.16 |
+------------------------------------+-------------+----------------+
| number-up-supported | OPTIONAL | Section 5.2.9 |
+------------------------------------+-------------+----------------+
| pages-per-minute-color | OPTIONAL | Section 5.4.37 |
+------------------------------------+-------------+----------------+
| pages-per-minute | OPTIONAL | Section 5.4.36 |
+------------------------------------+-------------+----------------+
| print-quality-supported | OPTIONAL | Section 5.2.13 |
+------------------------------------+-------------+----------------+
| printer-info | OPTIONAL | Section 5.4.6 |
+------------------------------------+-------------+----------------+
| printer-location | RECOMMENDED | Section 5.4.5 |
+------------------------------------+-------------+----------------+
| printer-make-and-model | RECOMMENDED | Section 5.4.9 |
+------------------------------------+-------------+----------------+
| printer-more-info | OPTIONAL | Section 5.4.7 |
+------------------------------------+-------------+----------------+
| printer-name | RECOMMENDED | Section 5.4.4 |
+------------------------------------+-------------+----------------+
| printer-resolution-supported | OPTIONAL | Section 5.2.12 |
+------------------------------------+-------------+----------------+
| printer-uri-supported | RECOMMENDED | Section 5.4.1 |
+------------------------------------+-------------+----------------+
| sides-supported | RECOMMENDED | Section 5.2.8 |
+------------------------------------+-------------+----------------+
| uri-authentication-supported | RECOMMENDED | Section 5.4.2 |
+------------------------------------+-------------+----------------+
| uri-security-supported | RECOMMENDED | Section 5.4.3 |
+------------------------------------+-------------+----------------+
Table 23: Attributes in Directory Entries
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Acknowledgements
The authors would like to acknowledge the following individuals for
their contributions to the original IPP/1.1 specifications:
Roger deBry, Tom Hastings (original RFC 2911 editor), Robert Herriot,
Scott A. Isaacson, Kirk Ocke, Patrick Powell, and Peter Zehler
Authors' Addresses
Michael Sweet
Apple Inc.
1 Infinite Loop
MS 111-HOMC
Cupertino, CA 95014
United States of America
Email: msweet@apple.com
Ira McDonald
High North, Inc.
PO Box 221
Grand Marais, MI 49839
United States of America
Phone: +1 906-494-2434
Email: blueroofmusic@gmail.com
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