Browse Prior Art Database

%INC5%Usage of Preempt/Resume techniques for Multimedia transport between routers

IP.com Disclosure Number: IPCOM000014883D
Original Publication Date: 1999-Nov-01
Included in the Prior Art Database: 2003-Jun-20
Document File: 5 page(s) / 41K

Publishing Venue

IBM

Related People

Didier Giroir: AUTHOR

Abstract

Usage of Preempt/Resume techniques for Multimedia transport within Router based networks

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 42% of the total text.

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  %INC5%Usage of Preempt/Resume techniques for Multimedia transport between routers

   Usage of Preempt/Resume techniques for Multimedia
transport within Router based networks

This paper relates to router based
telecommunication networks and, more
particularly, proposes the use of a
mechanism to improve the quality of
service provided by such router based
networks when different flows of
information, with different delay
constraints are considered. This paper
suggests to use between adjacent routers
within the network that are interconnected
via low speed links (i.e. Less than T3/E3
speeds), the improved preempt/resume
protocol
as described in "Method and
Apparatus for Transmission of High
Priority Traffic on High-Level Data Link
Control-Like or Frame Relay Networks".
This paper describing the improved
preempt/resume protocol has been published
in IBM's Topology Disclosure Bulletin v40
n1 p 1-4 in January 1997.

For router based communication networks,
there is a widely accepted requirement and
a large potential market for the transport
of some form of real time information,
alongside with the regular data packets.
Transporting variable length data packets
was the original scope of router
protocols, as opposed to Asynchronous
Transfer Mode technology which has
addressed from the very beginning the
transport of multiple categories of data,
including real time data. Transporting
real time data traffic within router based
networks allows for example, to use the
existing infrastructure to carry not only
computer related information but also the
packets associated with (usually) low or
medium quality voice circuits. Such real
time packets would otherwise have to be
transported over a totally different

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infrastructure than the router based
network, with all the associated
additional expenses.

Obtaining predictable performance that are
necessary when the transport of real time
information is concerned is fundamentally
harder for router-based networks than with
Time Division Multiplexing, Asynchronous
Transfer Mode or even Frame Relay
networks. The reason is that router
protocols by their connection-less nature
as of today have no concept of allocation
of channels with the reserved associated
resources within the network that are
generally considered to transport traffic
with strong delay and delay variation
characteristics.

Using this preempt/resume protocol between
routers allows the networks using low
speed lines (less than T3/E3 speeds)
between some or all of the nodes within
the network, to support the transport of
high priority traffic mixed with data
traffic with less stringent delay
constraints. The improved preempt/resume
protocol allows such networks to transport
delay sensitive information, such as voice
packets
. These voice packets may then
coexist with variable length data packets,
without the unacceptable impacts on delays
and delay variations for the real-time
traffic that are always associated with
low-speed lines when variable length data
packets of any size (up to the limits
imposed...