RFC 3051 (rfc3051) - Page 2 of 8


IP Payload Compression Using ITU-T V



Alternative Format: Original Text Document



RFC 3051        IP Payload Compression Using ITU-T V.44     January 2001


Table of Contents

    1. Introduction...................................................2
       1.1 General....................................................2
       1.2 Background of LZJH Data Compression........................2
       1.3 Intellectual Property Rights...............................3
       1.4 Specification of Requirements..............................4
    2. Compression Process............................................4
       2.1 Encoder Dictionary.........................................4
       2.2 Encoder Output.............................................4
       2.3 Padding....................................................4
    3. Decompression Process..........................................5
       3.1 Compressed Datagram........................................5
       3.2 Original Uncompressed Datagram.............................5
    4. IPComp Association (IPCA) Parameters...........................5
       4.1 Transform ID...............................................5
       4.2 Security Association Attributes............................5
       4.3 Manual configuration.......................................5
       4.4 Minimum packet size threshold..............................6
       4.5 Compressibility test.......................................6
    5. Security Considerations........................................6
    6. IANA Considerations............................................6
    7. Acknowledgements...............................................6
    8. References.....................................................6
    9. Authors' Addresses.............................................7
   10. Full Copyright Statement.......................................8

1. Introduction

1.1 General

   This document specifies the application of LZJH data compression, a
   lossless data compression algorithm, to IP datagram payloads.  LZJH
   data compression is to be used in conjunction with the IP Payload
   Compression Protocol (IPComp) [RFC 2393].  This document is written
   with the assumption that the reader has an understanding of the
   IPComp protocol.

1.2 Background of LZJH Data Compression

   LZJH is similar to the algorithm described in [LZ78] although it also
   has aspects which are similar to the algorithm described in [LZ77].
   As such, it provides the execution speed and low memory requirements
   of [LZ78] with compression ratios that are better than [LZ77].
   Originally developed for the satellite industry to compress IP
   datagrams independently, it is ideal for the IPComp application.  The
   LZJH algorithm was modified to compress a continuous stream of data
   for a modem environment and this modified version is the basis for



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