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RFC 7511
Independent Submission M. Wilhelm
Request for Comments: 7511 1 April 2015
Category: Informational
ISSN: 2070-1721
Scenic Routing for IPv6
Abstract
This document specifies a new routing scheme for the current version
of the Internet Protocol version 6 (IPv6) in the spirit of "Green
IT", whereby packets will be routed to get as much fresh-air time as
possible.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This is a contribution to the RFC Series, independently of any other
RFC stream. The RFC Editor has chosen to publish this document at
its discretion and makes no statement about its value for
implementation or deployment. Documents approved for publication by
the RFC Editor are not a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
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/rfc7511.
Copyright Notice
Copyright (c) 2015 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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Conventions and Terminology . . . . . . . . . . . . . . . 3
2. Scenic Routing . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Scenic Routing Option (SRO) . . . . . . . . . . . . . . . 3
3. Implications . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Routing Implications . . . . . . . . . . . . . . . . . . 5
3.2. Implications for Hosts . . . . . . . . . . . . . . . . . 5
3.3. Proxy Servers . . . . . . . . . . . . . . . . . . . . . . 6
4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
6. Related Work . . . . . . . . . . . . . . . . . . . . . . . . 6
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
7.1. Normative References . . . . . . . . . . . . . . . . . . 7
7.2. Informative References . . . . . . . . . . . . . . . . . 7
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 8
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
In times of Green IT, a lot of effort is put into reducing the energy
consumption of routers, switches, servers, hosts, etc., to preserve
our environment. This document looks at Green IT from a different
angle and focuses on network packets being routed and switched around
the world.
Most likely, no one ever thought about the millions of packets being
disassembled into bits every second and forced through copper wires
or being shot through dark fiber lines by powerful lasers at
continuously increasing speeds. Although RFC 5841 [RFC5841] provided
some thoughts about Packet Moods and began to represent them as a TCP
option, this doesn't help the packets escape their torturous routine.
This document defines another way to deal with Green IT for traffic
and network engineers and will hopefully aid the wellbeing of a
myriad of network packets around the world. It proposes Scenic
Routing, which incorporates the green-ness of a network path into the
routing decision. A routing engine implementing Scenic Routing
should therefore choose paths based on Avian IP Carriers [RFC1149]
and/or wireless technologies so the packets will get out of the
miles/kilometers of dark fibers that are in the ground and get as
much fresh-air time and sunlight as possible.
As of the widely known acceptance of the current version of the
Internet Protocol (IPv6), this document only focuses on version 6 and
ignores communication still based on Vintage IP [RFC791].
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1.1. Conventions and Terminology
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 RFC 2119 [RFC2119].
Additionally, the key words "MIGHT", "COULD", "MAY WISH TO", "WOULD
PROBABLY", "SHOULD CONSIDER", and "MUST (BUT WE KNOW YOU WON'T)" in
this document are to interpreted as described in RFC 6919 [RFC6919].
2. Scenic Routing
Scenic Routing can be enabled with a new option for IPv6 datagrams.
2.1. Scenic Routing Option (SRO)
The Scenic Routing Option (SRO) is placed in the IPv6 Hop-by-Hop
Options Header that must be examined by every node along a packet's
delivery path [RFC2460].
The SRO can be included in any IPv6 datagram, but multiple SROs MUST
NOT be present in the same IPv6 datagram. The SRO has no alignment
requirement.
If the SRO is set for a packet, every node en route from the packet
source to the packet's final destination MUST preserve the option.
The following Hop-by-Hop Option is proposed according to the
specification in Section 4.2 of RFC 2460 [RFC2460].
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Type | Option Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SRO Param | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Scenic Routing Option Layout
Option Type
8-bit identifier of the type of option. The option identifier
0x0A (On Air) is proposed for Scenic Routing.
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HEX act chg rest
--- --- --- -----
0A 00 0 01010 Scenic Routing
Figure 2: Scenic Routing Option Type
The highest-order two bits are set to 00 so any node not
implementing Scenic Routing will skip over this option and
continue processing the header. The third-highest-order bit
indicates that the SRO does not change en route to the packet's
final destination.
Option Length
8-bit unsigned integer. The length of the option in octets
(excluding the Option Type and Option Length fields). The value
MUST be greater than 0.
SRO Param
8-bit identifier indicating Scenic Routing parameters encoded as a
bit string.
+-+-+-+-+-+-+-+-+
| SR A W AA X Y |
+-+-+-+-+-+-+-+-+
Figure 3: SRO Param Bit String Layout
The highest-order two bits (SR) define the urgency of Scenic
Routing:
00 - Scenic Routing MUST NOT be used for this packet.
01 - Scenic Routing MIGHT be used for this packet.
10 - Scenic Routing SHOULD be used for this packet.
11 - Scenic Routing MUST be used for this packet.
The following BIT (A) defines if Avian IP Carriers should be used:
0 - Don't use Avian IP Carrier links (maybe the packet is
afraid of pigeons).
1 - Avian IP Carrier links may be used.
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The following BIT (W) defines if wireless links should be used:
0 - Don't use wireless links (maybe the packet is afraid of
radiation).
1 - Wireless links may be used.
The following two bits (AA) define the affinity for link types:
00 - No affinity.
01 - Avian IP Carriers SHOULD be preferred.
10 - Wireless links SHOULD be preferred.
11 - RESERVED
The lowest-order two bits (XY) are currently unused and reserved
for future use.
3. Implications
3.1. Routing Implications
If Scenic Routing is requested for a packet, the path with the known
longest Avian IP Carrier and/or wireless portion MUST be used.
Backbone operators who desire to be fully compliant with Scenic
Routing MAY WISH TO -- well, they SHOULD -- have separate MPLS paths
ready that provide the most fresh-air time for a given path and are
to be used when Scenic Routing is requested by a packet. If such a
path exists, the path MUST be used in favor of any other path, even
if another path is considered cheaper according to the path costs
used regularly, without taking Scenic Routing into account.
3.2. Implications for Hosts
Host systems implementing this option of receiving packets with
Scenic Routing requested MUST honor this request and MUST activate
Scenic Routing for any packets sent back to the originating host for
the current connection.
If Scenic Routing is requested for connections of local origin, the
host MUST obey the request and route the packet(s) over a wireless
link or use Avian IP Carriers (if available and as requested within
the SRO Params).
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System administrators MIGHT want to configure sensible default
parameters for Scenic Routing, when Scenic Routing has been widely
adopted by operating systems. System administrators SHOULD deploy
Scenic Routing information where applicable.
3.3. Proxy Servers
If a host is running a proxy server or any other packet-relaying
application, an application implementing Scenic Routing MUST set the
same SRO Params on the outgoing packet as seen on the incoming
packet.
Developers SHOULD CONSIDER Scenic Routing when designing and
implementing any network service.
4. Security Considerations
The security considerations of RFC 6214 [RFC6214] apply for links
provided by Avian IP Carriers.
General security considerations of wireless communication apply for
links using wireless technologies.
As the user is able to influence where flows and packets are being
routed within the network, this MIGHT influence traffic-engineering
considerations and network operators MAY WISH TO take this into
account before enabling Scenic Routing on their devices.
5. IANA Considerations
This document defines a new IPv6 Hop-by-Hop Option, the Scenic
Routing Option, described in Section 2.1. If this work is
standardized, IANA is requested to assign a value from the
"Destination Options and Hop-by-Hop Options" registry for the purpose
of Scenic Routing.
There are no IANA actions requested at this time.
6. Related Work
As Scenic Routing is heavily dependent on network paths and routing
information, it might be worth looking at designing extensions for
popular routing protocols like BGP or OSPF to leverage the full
potential of Scenic Routing in large networks built upon lots of
wireless links and/or Avian IP Carriers. When incorporating
information about links compatible with Scenic Routing, the routing
algorithms could easily calculate the optimal paths providing the
most fresh-air time for a packet for any given destination.
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This would even allow preference for wireless paths going alongside
popular or culturally important places. This way, the packets don't
only avoid the dark fibers, but they get to see the world outside of
the Internet and are exposed to different cultures around the globe,
which may help build an understanding of cultural differences and
promote acceptance of these differences.
7. References
7.1. Normative References
[RFC1149] Waitzman, D., "Standard for the transmission of IP
datagrams on avian carriers", RFC 1149, April 1990,
<http://www.rfc-editor.org/info/rfc1149>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998,
<http://www.rfc-editor.org/info/rfc2460>.
[RFC6214] Carpenter, B. and R. Hinden, "Adaptation of RFC 1149 for
IPv6", RFC 6214, April 2011,
<http://www.rfc-editor.org/info/rfc6214>.
[RFC6919] Barnes, R., Kent, S., and E. Rescorla, "Further Key Words
for Use in RFCs to Indicate Requirement Levels", RFC 6919,
April 2013, <http://www.rfc-editor.org/info/rfc6919>.
7.2. Informative References
[RFC5841] Hay, R. and W. Turkal, "TCP Option to Denote Packet Mood",
RFC 5841, April 2010,
<http://www.rfc-editor.org/info/rfc5841>.
[RFC791] Postel, J., "Internet Protocol", STD 5, RFC 791, September
1981, <http://www.rfc-editor.org/info/rfc791>.
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Acknowledgements
The author wishes to thank all those poor friends who were kindly
forced to read this document and that provided some nifty comments.
Author's Address
Maximilian Wilhelm
Paderborn, NRW
Germany
Phone: +49 176 62 05 94 27
EMail: max@rfc2324.org
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