PPP Gandalf FZA Compression Protocol
draft-ietf-pppext-gandalf-00
The information below is for an old version of the document that is already published as an RFC.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 1993.
|
|
|---|---|---|---|
| Authors | Abdulkader Barbir, William A. Simpson , David Carr | ||
| Last updated | 2013-03-02 (Latest revision 1993-10-26) | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | (None) | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 1993 (Informational) | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-pppext-gandalf-00
Network Working Group Dave Carr
Internet Draft Gandalf
expires in six months October 1993
PPP Gandalf FZA Compression Protocol
draft-ietf-pppext-gandalf-00.txt
Status of this Memo
This document is the product of the Point-to-Point Protocol Working
Group of the Internet Engineering Task Force (IETF). Comments should
be submitted to the ietf-ppp@ucdavis.edu mailing list.
Distribution of this memo is unlimited.
This document is an Internet Draft. Internet Drafts are working
documents of the Internet Engineering Task Force (IETF), its Areas,
and its Working Groups. Note that other groups may also distribute
working documents as Internet Drafts.
Internet Drafts are draft documents valid for a maximum of six
months. Internet Drafts may be updated, replaced, or obsoleted by
other documents at any time. It is not appropriate to use Internet
Drafts as reference material or to cite them other than as a
``working draft'' or ``work in progress.''
Please check the 1id-abstracts.txt listing contained in the
internet-drafts Shadow Directories on nic.ddn.mil, nnsc.nsf.net,
nic.nordu.net, ftp.nisc.sri.com, or munnari.oz.au to learn the
current status of any Internet Draft.
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 Gandalf FZA data compression
algorithm for compressing PPP encapsulated packets.
Carr expires in six months [Page i]
DRAFT Gandalf FZA October 1993
1. Introduction
FZA is a high performance LZA derivative which maximizes compression
at the expense of memory and CPU. Compression performance can be
adjusted based on CPU and memory available.
Multiple PPP packets can be combined in a single compressed frame, or
a single PPP packet can be spread across multiple frames.
1.1. Licensing
Source and object licenses are available on a non-discriminatory
basis for either a royalty or fixed price arrangement. Patent
indemnity is included with the license.
Carr expires in six months [Page 1]
DRAFT Gandalf FZA October 1993
2. FZA Packets
Before any FZA packets may be communicated, PPP must reach the
Network-Layer Protocol phase, and the CCP Control Protocol must reach
the Opened state.
Exactly one FZA datagram is encapsulated in the PPP Information
field, where the PPP Protocol field indicates type hex 00FD
(compressed datagram).
The maximum length of the FZA datagram transmitted over a PPP link is
the same as the maximum length of the Information field of a PPP
encapsulated packet.
Prior to compression, the uncompressed data begins with the PPP
Protocol number. This value MAY be compressed when Protocol-Field-
Compression is negotiated.
PPP Link Control Protocol packets MUST NOT be sent within compressed
data.
Padding
The FZA packets require the negotiation of the Self-Describing-
Padding Configuration Option [3] at LCP Link Establishment.
Reliability and Sequencing
The FZA algorithm expects a reliable link, as described in "PPP
Reliable Transmission" [4].
Gandalf FZA expects the packets to be delivered in sequence.
Data Expansion
The maximum expansion of Gandalf FZA is 2:1. However, typical
expansion on pre-compressed data is 1.01:1. Expanded data is sent
to maintain the integrity of the compression history.
When the expansion exceeds the size of the peer's Maximum Receive
Unit for the link, the expanded packet is sent in multiple PPP
frames. The compressed data contains an indication of the end of
the original packet.
Carr expires in six months [Page 2]
DRAFT Gandalf FZA October 1993
2.1. Packet Format
A summary of the Gandalf FZA packet format is shown below. The
fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PPP Protocol | Compressed Data ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
PPP Protocol
The PPP Protocol field is described in the Point-to-Point Protocol
Encapsulation [1].
When the Gandalf FZA compression protocol is successfully
negotiated by the PPP Compression Control Protocol [2], the value
is 00FD hex. This value MAY be compressed when Protocol-Field-
Compression is negotiated.
Compressed Data
The compressed PPP encapsulated packet.
Carr expires in six months [Page 3]
DRAFT Gandalf FZA October 1993
3. Configuration Option Format
Description
The CCP Gandalf-FZA Configuration Option negotiates the use of
Gandalf FZA on the link. By default or ultimate disagreement, no
compression is used.
A summary of the Gandalf-FZA Configuration Option format is shown
below. The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | History | Data ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
6
Length
>= 3
History
The History field specifies the maximum size of the compression
history in powers of 2. Valid values range from 12 to 15.
Data
Zero or more octets of additional configuration information. Any
implementation which does not implement this information MUST send
a Configure-Nak without this field.
Carr expires in six months [Page 4]
DRAFT Gandalf FZA October 1993
Security Considerations
Security issues are not discussed in this memo.
References
[1] Simpson, W.A., "The Point-to-Point Protocol (PPP)", work in
progress.
[2] Rand, D., "The PPP Compression Control Protocol (CCP)", work in
progress.
[3] Simpson, W.A., "PPP LCP Extensions", work in progress.
[4] Rand, D., "PPP Reliable Transmission", work in progress.
Acknowledgments
Editting and formatting by Bill Simpson.
Carr expires in six months [Page 5]
DRAFT Gandalf FZA October 1993
Chair's Address
The working group can be contacted via the current chair:
Fred Baker
Advanced Computer Communications
315 Bollay Drive
Santa Barbara, California 93117
EMail: fbaker@acc.com
Author's Address
Questions about this memo can also be directed to:
Dave Carr
Gandalf Data Limited
130 Colonnade Road South
Napean, Ontario, Canada K2E 7M4
(613) 723-6500
(613) 226-1717 Fax
Email: dcarr@gandalf.ca
Carr expires in six months [Page 6]
DRAFT Gandalf FZA October 1993
Table of Contents
1. Introduction .......................................... 1
1.1 Licensing ....................................... 1
2. FZA Packets ........................................... 2
2.1 Packet Format ................................... 3
3. Configuration Option Format ........................... 4
SECURITY CONSIDERATIONS ...................................... 5
REFERENCES ................................................... 5
ACKNOWLEDGEMENTS ............................................. 5
CHAIR'S ADDRESS .............................................. 6
AUTHOR'S ADDRESS ............................................. 6
Bill.Simpson@um.cc.umich.edu