As per Relevance of the word resource, we have this rfc below:
Network Working Group D.
Request for Comments: 1975 J.
Category: Informational J.
August 1996
PPP Magnalink Variable Resource
Status of This
This memo provides information for the Internet community. This
does not specify an Internet standard of any kind. Distribution
this memo is unlimited
The Point-to-Point Protocol (PPP) [1] provides a standard method
encapsulating multiple protocol datagrams over point-to-point links
The PPP Compression Control Protocol [2] provides a method
negotiating data compression over PPP links
The Magnalink Variable Resource Compression Algorithm (MVRCA)
a wide range of interoperable compression implementations
performance characteristics are a function of available CPU
memory resources
The Magnalink variable resource compression algorithm defines
family of interoperable compression solutions with
performance as a function of available CPU and memory resources.
addresses the need for an algorithm which can be tailored to
system on which it is implemented without
interoperability
Source licenses are available on a non-discriminatory basis
The contact person for evaluation under NDA and Licensing is
Director of OEM
Magnalink Communications
Telco Systems Inc
63 Nahatan
Norwood, Mass. 02062
Phone: (617) 255-9400, Fax: (617) 255-5885
oem@magna.telco.
Schremp, Black & Weiss Informational [Page 1]
RFC 1975 PPP Magnalink Variable Resource Compression August 1996
MVRCA
Before any MVRCA packets may be communicated, PPP must reach
Network-Layer Protocol phase[1], and the Compression Control
must reach the Opened state
The text of a Packet to be compressed begins with PPP
number. The Packet header including the PPP Protocol number may
already been compressed when Protocol-Field-Compression has
negotiated
Reliability and
MVRCA packets may be sent across an unreliable link or may use
reliable link as described in "PPP Reliable Transmission"[3] if
reliable link has been negotiated. If frames are delivered out
order or a frame is dropped, the decompressor will detect this
requests a resynchronization using the Reset-Req and Reset-Ack
of the CCP[2], with the compressor for the affected context
Data
Although the compression algorithm may occasionally expand a
packet, there is no expansion in MVRCA since any expanded data
instead sent uncompressed. Dictionary synchronization is
across uncompressed packets
The encapsulation consists of the PPP Protocol Identifier, a bit
indicate if the data is compressed, the Context Identifier(CID),
proprietary flag bit (E), a Packet Integrity Byte(PIB), and
Compressed data
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PPP Protocol Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|C|E| CID | PIB | C compressed
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1 data is
| Compressed data ... 0 data is not
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Schremp, Black & Weiss Informational [Page 2]
RFC 1975 PPP Magnalink Variable Resource Compression August 1996
Compressed/Uncompressed Flag (C
When attempting to compress certain types of Packets or Fragments
compressor may not be effective. When this occurs the
data is added to the compression History Buffer and sent across
link in frame with the Compressed/Uncompressed Flag(C) set to 0.
Context Identifier (CID
Since PPP will transport multiple protocol datagrams it may
advantageous to compress each protocol or each virtual circuit in
different History Buffer or Context. The CID allows the compressor
indicate to the decompressor which History Buffer the
decided to use for a given Packet. The basis of this decision is
to the implementor. The number of buffers and size of each buffer
negotiated
A CID of 0 indicates that the Packet by Packet context will be
if it has been negotiated. The Packet by Packet context is
between Packets so that this History Buffer is not maintained
Packet boundaries
Packet Integrity Byte (PIB
To ensure that Packets are being compressed and
correctly and to ensure History Buffer synchronization is maintained
a Packet Integrity Byte is added to the packet header
The packet integrity byte is defined in the full
specification
Configuration Option
The CCP MVRCA Configuration Option negotiates the use of MVRCA on
link. By default or ultimate disagreement, no compression is used
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 |FE |P| History | # Contexts |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Schremp, Black & Weiss Informational [Page 3]
RFC 1975 PPP Magnalink Variable Resource Compression August 1996
24
4
FE -
Negotiates features specific to this compression algorithm
Defines the size of the compression history buffer. Valid values
defined in the full protocol specification
#
This is the number of contexts. Each context implies the creation
a History Buffer for that context of the size indicated in
Context History field. Values are 1-63. This value includes
the Packet by Packet context and the number of contexts for
history is maintained. Therefore, when this value is 1 and the
(Packet by Packet) flag is also 1, then only in packet compression
supported and history context is not retained across
boundaries. The Context Identifier (CID) starts with 1 for
where the history is maintained
P - Packet by Packet
When 1, packet by packet compression is enabled for the context
context ID is 0. When P is 0, packet by packet compression is
supported
Schremp, Black & Weiss Informational [Page 4]
RFC 1975 PPP Magnalink Variable Resource Compression August 1996
Security
Security issues are not discussed in this memo
[1] Simpson, W., Editor, "The Point-to-Point Protocol (PPP)", STD 51,
RFC 1661, July 1994.
[2] Rand, D., "The PPP Compression Control Protocol (CCP)", RFC 1962,
June 1996.
[3] Rand, D., "PPP Reliable Transmission", RFC 1663, July 1994.
Chair's
The working group can be contacted via the current chair
Karl
Ascend
3518 Riverside Drive, Suite 101
Columbus, Ohio 43221
EMail: karl@ascend.
Schremp, Black & Weiss Informational [Page 5]
RFC 1975 PPP Magnalink Variable Resource Compression August 1996
Authors'
Comments about this document may also be directed to the authors
Doug
Telco Systems, Inc
Magnalink Communications
63 Nahatan
Norwood Ma. 02062
Phone: (617) 255-9400
EMail: dhs@magna.telco.
Jeffrey
Telco Systems, Inc
Magnalink Communications
63 Nahatan
Norwood Ma. 02062
Phone: (617) 255-9400
EMail: jtb@magna.telco.
Jeffrey
Telco Systems, Inc
Magnalink Communications
63 Nahatan
Norwood Ma. 02062
Phone: (617) 255-9400
EMail: jaw@magna.telco.
Schremp, Black & Weiss Informational [Page 6]
if you see any problems within the linking, don't worry be happy,
this is version 0.1 of the Relevance System and you gotta expect some crappy subroutines sometimes,
just be content we did not write this in Java, which would have made this "bigger and better" HAHAHHA.
RFC documents can be found at I.E.T.F.
Relevance System Copyright © 2002 Spectrum WorldResearch
other technical nosh by ServerMasters Corporation
collaboration of BobX
