RFC 3321 (rfc3321) - Page 2 of 19

Signaling Compression (SigComp) - Extended Operations

RFC 3321             SigComp - Extended Operations          January 2003


Table of Contents

   1.  Introduction..................................................2
   2.  Terminology...................................................3
   3.  Architectural View of Feedback................................4
   4.  State Reference Model.........................................5
   5.  Extended Mechanisms...........................................6
   6.  Implications on SigComp......................................13
   7.  Security Considerations......................................17
   8.  IANA Considerations..........................................17
   9.  Acknowledgements.............................................17
   10. Intellectual Property Right Considerations...................17
   11. References...................................................17
   12. Authors' Addresses...........................................18
   13. Full Copyright Statement.....................................19

1.  Introduction

   This document describes how to implement mechanisms with [SIGCOMP] to
   significantly improve the compression efficiency compared to per-
   message compression.

   One such mechanism is to use previously sent messages in the SigComp
   compression process, referred to as dynamic compression.  In order to
   utilize information from previously sent messages, it is necessary
   for a compressor to gain knowledge about the reception of these
   messages.  For a reliable transport, such as TCP, this is guaranteed.
   For an unreliable transport however, the SigComp protocol can be used
   to provide such a functionality itself.  That functionality is
   described in this document and is referred to as explicit
   acknowledgement.

   Another mechanism that will improve the compression efficiency of
   SigComp, especially when SigComp is applied to protocols that are of
   request/response type, is shared compression.  This involves using
   received messages in the SigComp compression process.  In particular
   the compression of the first few messages will gain from shared
   compression.  Shared compression is described in this document.

   For better understanding of this document the reader should be
   familiar with the concept of [SIGCOMP].










Hannu, et. al.               Informational