conex Working Group S. Krishnan
Internet-Draft Ericsson
Intended status: Standards Track M. Kuehlewind
Expires: April 26, 2012 IKR University of Stuttgart
C. Ucendo
Telefonica
October 24, 2011
IPv6 Destination Option for Conex
draft-ietf-conex-destopt-00
Abstract
Conex is a mechanism by which senders inform the network about the
congestion encountered by packets earlier in the same flow. This
document specifies an IPv6 destination option that is capable of
carrying conex markings in IPv6 datagrams.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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and may be updated, replaced, or obsoleted by other documents at any
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This Internet-Draft will expire on April 26, 2012.
Copyright Notice
Copyright (c) 2011 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
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to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions used in this document . . . . . . . . . . . . . . . 3
3. Background . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Conex Destination Option (CDO) . . . . . . . . . . . . . . . . 4
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5
6. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
8. Normative References . . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5
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1. Introduction
Conex [CAM] is a mechanism by which senders inform the network about
the congestion encountered by packets earlier in the same flow. This
document specifies an IPv6 destination option [RFC2460] that can be
used for performing conex markings in IPv6 datagrams.
2. Conventions used in this document
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].
3. Background
The Conex working group came up with a list of requirements that had
to be met by any marking mechanism. It then considered several
alternative mechanisms and evaluated their suitability for conex
marking. There were no mechanisms found that were completely
suitable, but the only mechanism that came close to meeting the
requirements was IPv6 destination options. The analysis of the
different alternatives can be found in [draft-krishnan-conex-ipv6].
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4. Conex Destination Option (CDO)
The Conex Destination Option (CDO) is a destination option that can
be included in IPv6 datagrams that are sent by conex-aware senders in
order to inform conex-aware nodes on the path about the CDO has an
alignment requirement of (none).
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X|L|E|C| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Conex Destination Option Layout
Option Type
8-bit identifier of the type of option. The option identifier
for the conex destination option will be allocated by the IANA.
Option Length
8-bit unsigned integer. The length of the option (excluding
the Option Type and Option Length fields). This field MUST be
set to the value 4.
X Bit
When this bit is set, the transport sender is using ConEx with
this packet. If it is reset, the sender is not using ConEx.
L Bit
When this bit is set, the transport sender has experienced a loss.
If it is reset, the sender has not experienced a loss.
E Bit
When this bit is set, the transport sender has experienced
ECN-signaled congestion. If it is reset, the sender has not
experienced ECN-signaled congestion.
C Bit
When this bit is set, the transport sender is building up
congestion credit. Otherwise it is not.
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5. Acknowledgements
The authors would like to thank Marcelo Bagnulo, Bob Briscoe, Ingemar
Johansson, Joel Halpern and John Leslie for the discussions that led
to this document.
6. Security Considerations
This document does not bring up any new security issues.
7. IANA Considerations
This document defines a new IPv6 destination option for carrying
conex markings. IANA is requested to assign a new destination option
type in the Destination Options registry maintained at
http://www.iana.org/assignments/ipv6-parameters <TBA1> Conex
Destination Option [RFCXXXX] The act bits for this option need to be
10 and the chg bit needs to be 0.
8. Normative References
[CAM] Briscoe, B., "Congestion Exposure (ConEx) Concepts and
Abstract Mechanism", draft-ietf-conex-abstract-mech-01
(work in progress), March 2011.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998.
Authors' Addresses
Suresh Krishnan
Ericsson
8400 Blvd Decarie
Town of Mount Royal, Quebec
Canada
Email: suresh.krishnan@ericsson.com
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Mirja Kuehlewind
IKR University of Stuttgart
Email: mirja.kuehlewind@ikr.uni-stuttgart.de
Carlos Ralli Ucendo
Telefonica
Email: ralli@tid.es
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