RObust Header Compression (ROHC): A Compression Profile for IP
RFC 3843
Document | Type |
RFC - Proposed Standard
(June 2004; No errata)
Updated by RFC 4815
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Authors | Lars-Erik Jonsson , Ghyslain Pelletier | ||
Last updated | 2013-03-02 | ||
Stream | Internet Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 3843 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Allison Mankin | ||
Send notices to | (None) |
Network Working Group L-E. Jonsson Request for Comments: 3843 G. Pelletier Category: Standards Track Ericsson June 2004 RObust Header Compression (ROHC): A Compression Profile for IP Status of this Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2004). Abstract The original RObust Header Compression (ROHC) RFC (RFC 3095) defines a framework for header compression, along with compression protocols (profiles) for IP/UDP/RTP, IP/ESP (Encapsulating Security Payload), IP/UDP, and also a profile for uncompressed packet streams. However, no profile was defined for compression of IP only, which has been identified as a missing piece in RFC 3095. This document defines a ROHC compression profile for IP, similar to the IP/UDP profile defined by RFC 3095, but simplified to exclude UDP, and enhanced to compress IP header chains of arbitrary length. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology. . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. ROHC IP Compression (Profile 0x0004) . . . . . . . . . . . . . 3 3.1. Static Chain Termination . . . . . . . . . . . . . . . . 3 3.2. Handling Multiple Levels of IP Headers . . . . . . . . . 3 3.3. Constant IP-ID . . . . . . . . . . . . . . . . . . . . . 4 3.4. Additional Mode Transition Logic . . . . . . . . . . . . 6 3.5. Initialization . . . . . . . . . . . . . . . . . . . . . 8 3.6. Packet Types . . . . . . . . . . . . . . . . . . . . . . 8 3.7. The CONTEXT_MEMORY Feedback Option . . . . . . . . . . . 10 4. Security Considerations. . . . . . . . . . . . . . . . . . . . 10 5. IANA Considerations. . . . . . . . . . . . . . . . . . . . . . 10 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10 7. Normative References . . . . . . . . . . . . . . . . . . . . . 11 Jonsson & Pelletier Standards Track [Page 1] RFC 3843 A ROHC Profile for IP June 2004 Appendix A. Detailed Procedures for Canceling Mode Transitions. . 12 A.1. Transition from Optimistic to Reliable Mode. . . . . . . 12 A.2. Transition from Unidirectional to Reliable Mode. . . . . 13 A.3. Transition from Reliable to Optimistic Mode. . . . . . . 13 A.4. Transition Back to Unidirectional Mode . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . 16 1. Introduction The original RObust Header Compression (ROHC) RFC [RFC-3095] defines a framework for header compression, along with compression protocols (profiles) for IP/UDP/RTP, IP/ESP (Encapsulating Security Payload), IP/UDP, and also a profile for uncompressed packet streams. The profile for uncompressed data was defined to provide a means to encapsulate all traffic over a link within ROHC packets. Through this profile, the lower layers do not have to provide multiplexing for different packet types, but instead ROHC can handle any packet stream, even if compression profiles for all kinds of packet streams have not yet been defined or implemented over the link. Although the profile without compression is simple and can tunnel arbitrary packets, it has of course a major weakness in that it does not compress the headers at all. When considering that normally all packets are expected to be IP [RFC-791, RFC-2460] packets, and that the IP header often represents a major part of the total header, a useful alternative to no compression would for most packets be compression of the IP header only. Unfortunately, such a profile was not defined in [RFC-3095], and this has thus been identified as an important missing piece in the ROHC toolbox. This document addresses this missing compression support and defines a ROHC compression profile for IP [RFC-791, RFC-2460] only, similar to the IP/UDP profile defined by [RFC-3095], but simplified to exclude UDP. Due to the similarities with the IP/UDP profile, the IP compression profile is described based on the IP/UDP profile, mainly covering differences. The most important differences are a different way of terminating the static header chain, and the capability of compressing IP header chains of arbitrary length.Show full document text