From the introduction in RFC 3320:

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 RFC2960.

  • RFC3320: Signaling Compression (SigComp)
  • RFC3321: Signaling Compression (SigComp) - Extended Operations
  • RFC3485: The Session Initiation Protocol (SIP) and Session Description Protocol (SDP) Static Dictionary for Signaling Compression (SigComp)
  • RFC4077: A Negative Acknowledgement Mechanism for Signaling Compression
  • RFC4464: Signaling Compression (SigComp) Users' Guide
  • RFC4465: Signaling Compression (SigComp) Torture Tests
  • RFC4896:Signaling Compression (SigComp) Corrections and Clarifications
  • RFC5049: Applying Signaling Compression (SigComp) to the Session Initiation Protocol (SIP)
  • RFC5112: The Presence-Specific Static Dictionary for Signaling Compression (Sigcomp)
  • RFC1662: PPP in HDLC-like Framing
  • RFC1951: DEFLATE Compressed Data Format Specification version
  • RFC3174: US Secure Hash Algorithm 1 (SHA1)
  • 3GPP TR23.979 Annex C: Required SigComp performance

  • libSigComp: An open source SigComp API under LGPLv3

Created by: oej, Last modification: Wed 13 of Jun, 2012 (05:43 UTC) by admin
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