datatracker.ietf.org
Sign in
Version 5.6.2.p6, 2014-09-03
Report a bug

Microsoft Point-To-Point Compression (MPPC) Protocol
RFC 2118

Document type: RFC - Informational (March 1997; No errata)
Document stream: IETF
Last updated: 2013-03-02
Other versions: plain text, pdf, html

IETF State: (None)
Document shepherd: No shepherd assigned

IESG State: RFC 2118 (Informational)
Responsible AD: (None)
Send notices to: No addresses provided

Network Working Group                                            G. Pall
Request for Comments: 2118                         Microsoft Corporation
Category: Informational                                       March 1997

          Microsoft Point-To-Point Compression (MPPC) Protocol

Status of this Memo

   This memo provides information for the Internet community.  This memo
   does not specify an Internet standard of any kind.  Distribution of
   this memo is unlimited.

Abstract

   The Point-to-Point Protocol (PPP) [1] provides a standard method for
   transporting multi-protocol datagrams over point-to-point links.

   The PPP Compression Control Protocol [2] provides a method to
   negotiate and utilize compression protocols over PPP encapsulated
   links.

   This document describes the use of the Microsoft Point to Point
   Compression protocol (also referred to as MPPC in this document) for
   compressing PPP encapsulated packets.

Table of Contents

   1.     Introduction ..........................................    2
      1.1       Licensing .......................................    2
      1.2.      Specification of Requirements ...................    2
   2.     Configuration Option Format ...........................    3
   3.     MPPC Packets ..........................................    4
      3.1       Packet Format....................................    5
   4. Description of Compressor and Encoding ....................    6
      4.1       Literal Encoding ................................    7
      4.2       Copy Tuple Encoding .............................    7
          4.2.1     Offset Encoding .............................    7
          4.2.2     Length-of-Match Encoding ....................    7
      4.3       Synchronization .................................    8
   SECURITY CONSIDERATIONS ......................................    8
   REFERENCES ...................................................    9
   ACKNOWLEDGEMENTS .............................................    9
   CHAIR'S ADDRESS    ...........................................    9
   AUTHORS' ADDRESS .............................................    9

Pall                         Informational                      [Page 1]
RFC 2118                     MPPC Protocol                    March 1997

1.  Introduction

   The Microsoft Point to Point Compression scheme is a means of
   representing arbitrary Point to Point Protocol (PPP) packets in a
   compressed form. The MPPC algorithm is designed to optimize processor
   utilization and bandwidth utilization in order to support large
   number of simultaneous connections. The MPPC algorithm is also
   optimized to work efficiently in typical PPP scenarios
   (1500 byte MTU, etc.).

   The MPPC algorithm uses an LZ [3] based algorithm with a sliding
   window history buffer.

   The MPPC algorithm keeps a continous history so that after 8192 bytes
   of data has been transmitted compressed there is always 8192 bytes of
   history to use for compressing, except when the history is flushed.

1.1.  Licensing

   MPPC can only be used in products that implement the Point to Point
   Protocol AND for the sole purpose of interoperating with other MPPC
   and Point to Point Protocol implementations.

   Source and object licenses are available on a non-discriminatory
   basis from Stac Electronics. Please contact:

         Cheryl Poland
         Stac Electronics
         12636 High Bluff Drive,
         San Deigo, CA 92130
         Phone: (619)794-4534
         Email: cherylp@stac.com

1.2.  Specification of Requirements

   In this document, several words are used to signify the requirements
   of the specification.  These words are often capitalized.

   MUST      This word, or the adjective "required", means that the
             definition is an absolute requirement of the specification.

   MUST NOT  This phrase means that the definition is an absolute
             prohibition of the specification.

Pall                         Informational                      [Page 2]
RFC 2118                     MPPC Protocol                    March 1997

   SHOULD    This word, or the adjective "recommended", means that there
             may exist valid reasons in particular circumstances to
             ignore this item, but the full implications MUST be
             understood and carefully weighed before choosing a
             different course.

   MAY       This word, or the adjective "optional", means that this
             item is one of an allowed set of alternatives.  An
             implementation which does not include this option MUST be
             prepared to interoperate with another implementation which

[include full document text]