Browse Prior Art Database

Normalized Multiprotocol Packet Processor

IP.com Disclosure Number: IPCOM000105305D
Original Publication Date: 1993-Jul-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 93K

Publishing Venue

IBM

Related People

Koufopavlou, OG: AUTHOR [+3]

Abstract

In multiprotocol communication subsystems, packets pertaining to different protocol suites may be received at a network interface adapter. Each packet has to be processed according to its corresponding protocol. In uniprocessor software implementations, this usually involves task switching, which is generally a time consuming operation. Another alternative is to replicate the protocol processing hardware in order to provide a separate hardware path for each protocol suite. This is a costly and space consuming solution.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Normalized Multiprotocol Packet Processor

      In multiprotocol communication subsystems, packets pertaining
to different protocol suites may be received at a network interface
adapter.  Each packet has to be processed according to its
corresponding protocol.  In uniprocessor software implementations,
this usually involves task switching, which is generally a time
consuming operation.  Another alternative is to replicate the
protocol processing hardware in order to provide a separate hardware
path for each protocol suite.  This is a costly and space consuming
solution.

      Disclosed is a method of implementing multiprotocol packet
processing where packets are reformatted into a normalized format
that keeps all original protocol information imbedded in the header
and trailer of a packet (along with an identifier for the original
protocol suite).  A single processor running a single task then
processes all packets in the same way.  Reconversion to the original
format can be done if necessary.  A clear application of this
disclosure is in multiprotocol routers.  Furthermore, it is a well
known fact that router designers consider multiprotocol processing to
be one of the major bottlenecks in multiprotocol routers.

      In communication subsystems capable of handling packets
pertaining to various protocol suites, a major implementation issue
that affects their overall performance relates to the method used in
handling the different packets, which usually arrive randomly
interleaved.

      The usual uniprocessor software implementation of such
multiprotocol systems, defines each protocol (or protocol suite) as a
separate task.  The alternation among different tasks -due to the
arrival of subsequent packets pertaining to different protocols- is
usually done by task switching.  This is generally a very time
consuming operation on almost all processors existing today.

      An alternative approach would be to simply replicate the
protocol processing subsystem and provide one for each protocol.  In
this case, a sorter is used to direct each packet to the proper
processor.  It is also possible to dedicate one processor to each
frequently used protocol while using one processor for a group of
infrequent protocols.  In any c...