RFC 1974 (rfc1974) - Page 1 of 20
PPP Stac LZS Compression Protocol
Alternative Format: Original Text Document
Network Working Group R. Friend
Request for Comments: 1974 Stac Electronics
Category: Informational W. Simpson
DayDreamer
August 1996
PPP Stac LZS Compression 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 Stac LZS data compression
algorithm, with single or multiple compression histories, for
compressing PPP encapsulated packets.
Table of Contents
1. Introduction .......................................... 2
1.1 Licensing ....................................... 2
1.2 Specification of Requirements ................... 3
2. LZS Packets ........................................... 3
2.1 Padding ......................................... 4
2.2 Zero Deletion/Insertion ......................... 4
2.3 Reliability and Sequencing ...................... 4
2.3.1 Reset-Request and Reset-Ack Packet Formats....... 5
2.4 Data Expansion .................................. 6
2.5 Packet Format ................................... 6
2.5.1 PPP Protocol .................................... 7
2.5.2 History Number .................................. 7
2.5.3 Check Value ..................................... 7
2.5.3.1 LCB ........................................ 7
2.5.3.2 CRC ........................................ 7
2.5.3.3 Sequence Number ............................ 8
2.5.3.3.1 History Synchronization with Sequence
Numbers Example ...................... 9
Friend & Simpson Informational