Signaling Compression (SigComp)
RFC 3320
Document | Type |
RFC - Proposed Standard
(January 2003; No errata)
Updated by RFC 4896
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|
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Authors | Jan Christoffersson , Carsten Bormann , Hans Hannu , Richard Price , Zhigang Liu , Jonathan Rosenberg | ||
Last updated | 2013-03-02 | ||
Replaces | draft-ietf-rohc-sigcomp-algorithm, draft-ietf-rohc-sigcomp-udvm | ||
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 3320 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Allison Mankin | ||
IESG note | Responsible: RFC Editor | ||
Send notices to | <cabo@tzi.org>, <lars-erik.jonsson@ericsson.com> |
Network Working Group R. Price Request for Comments: 3320 Siemens/Roke Manor Category: Standards Track C. Bormann TZI/Uni Bremen J. Christoffersson H. Hannu Ericsson Z. Liu Nokia J. Rosenberg dynamicsoft January 2003 Signaling Compression (SigComp) 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 (2003). All Rights Reserved. Abstract This document defines Signaling Compression (SigComp), a solution for compressing messages generated by application protocols such as the Session Initiation Protocol (SIP) (RFC 3261) and the Real Time Streaming Protocol (RTSP) (RFC 2326). The architecture and prerequisites of SigComp are outlined, along with the format of the SigComp message. Decompression functionality for SigComp is provided by a Universal Decompressor Virtual Machine (UDVM) optimized for the task of running decompression algorithms. The UDVM can be configured to understand the output of many well-known compressors such as DEFLATE (RFC-1951). Price, et. al. Standards Track [Page 1] RFC 3320 Signaling Compression (SigComp) January 2003 Table of Contents 1. Introduction...................................................2 2. Terminology....................................................3 3. SigComp architecture...........................................5 4. SigComp dispatchers...........................................15 5. SigComp compressor............................................18 6. SigComp state handler.........................................20 7. SigComp message format........................................23 8. Overview of the UDVM..........................................28 9. UDVM instruction set..........................................37 10. Security Considerations.......................................56 11. IANA Considerations...........................................58 12. Acknowledgements..............................................59 13. References....................................................59 14. Authors' Addresses............................................60 15. Full Copyright Statement......................................62 1. Introduction Many application protocols used for multimedia communications are text-based and engineered for bandwidth rich links. As a result the messages have not been optimized in terms of size. For example, typical SIP messages range from a few hundred bytes up to two thousand bytes or more [RFC3261]. With the planned usage of these protocols in wireless handsets as part of 2.5G and 3G cellular networks, the large message size is problematic. With low-rate IP connectivity the transmission delays are significant. Taking into account retransmissions, and the multiplicity of messages that are required in some flows, call setup and feature invocation are adversely affected. SigComp provides a means to eliminate this problem by offering robust, lossless compression of application messages. This document outlines the architecture and prerequisites of the SigComp solution, the format of the SigComp message and the Universal Decompressor Virtual Machine (UDVM) that provides decompression functionality. SigComp is offered to applications as a layer between the application and an underlying transport. The service provided is that of the underlying transport plus compression. SigComp supports a wide range of transports including TCP, UDP and SCTP [RFC-2960]. Price, et. al. Standards Track [Page 2] RFC 3320 Signaling Compression (SigComp) January 2003 2. 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 BCP 14, RFC 2119Show full document text