RFC 2395 (rfc2395) - Page 2 of 9

IP Payload Compression Using LZS

RFC 2395            IP Payload Compression Using LZS       December 1998


   9. Appendix: Compression Efficiency versus Datagram Size..........8
   10. Full Copyright Statement......................................9

1. Introduction

1.1 General

   This document specifies the application of LZS compression, a
   lossless compression algorithm, to IP datagram payloads. This
   document is to be used in conjunction with the IP Payload Compression
   Protocol [IPCOMP].  This specification assumes a thorough
   understanding of the IPComp protocol.

1.2 Background of LZS Compression

   Starting with a sliding window compression history, similar to [LZ1],
   Hi/fn developed a new, enhanced compression algorithm identified as
   LZS. The LZS algorithm is a general purpose lossless compression
   algorithm for use with a wide variety of data types.  Its encoding
   method is very efficient, providing compression for strings as short
   as two octets in length.

   The LZS algorithm uses a sliding window of 2,048 bytes.  During
   compression, redundant sequences of data are replaced with tokens
   that represent those sequences. During decompression, the original
   sequences are substituted for the tokens in such a way that the
   original data is exactly recovered. LZS differs from lossy
   compression algorithms, such as those often used for video
   compression, that do not exactly reproduce the original data.

   The details of LZS compression can be found in [ANSI94].

   The efficiency of the LZS algorithm depends on the degree of
   redundancy in the original data.  A table of compression ratios for
   the [Calgary] Corpus file set is provided in the appendix in Section
   7.















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