BSD, PPP BSD Compression Protocol

Protocol suite:	PPP.
PPP protocol:	PPP compression protocol.
CCP option:	21.
SNMP MIBs:
Working groups:	pppext, Point-to-Point Protocol Extensions.
Links:

Used for compressing PPP encapsulated packets.

RFC 1977, pages 1 and 2:

UNIX compress as embodied in the freely and widely distributed BSD source has the following features:

Dynamic table clearing when compression becomes less effective.

Automatic turning off of compression when the overall result is not smaller than the input.

Dynamic choice of code width within predetermined limits.

Heavily used for many years in networks, on modem and other point-to-point links to transfer netnews.

An effective code width requires less than 64KBytes of memory on both sender and receive.

BSD UNIX compress command source is widely and freely available, with no additional license for many computer vendors. The included source code is based on the BSD compress command source and carries only the copyright of The Regents of the University of California. Use the code entirely at your own risk. It has no warranties or indemnifications of any sort. Note that there are patents on LZW.

Before any BSD Compress packets may be communicated, PPP must reach the Network-Layer Protocol phase, and the CCP Control Protocol must reach the Opened state.

Glossary:

RFCs:

[RFC 1977] PPP BSD Compression Protocol.

Publications:

Obsolete RFCs: