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Prioritized Adaptive Routing in a Packet Switched Network

IP.com Disclosure Number: IPCOM000084429D
Original Publication Date: 1975-Nov-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

Friedman, SW: AUTHOR [+3]

Abstract

Nodal exchange facilities, in a packet switched network for data communication, may employ a selection algorithm to determine the path over which data traffic is to be routed (i.e., stored and forwarded in multibit packet units). The illustration suggests choices available for multinode path selection. Traffic between host stations A and B is routed through the nodal exchange facilities a, b. If the "short" path currently presents three units of processing and transmission delay and the "longer" path (via nodal exchange facility c) encompasses six units of processing and transmission delay, it is more efficient to use the shorter path. However, when the shorter path is occupied to capacity the longer path must be used.

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Prioritized Adaptive Routing in a Packet Switched Network

Nodal exchange facilities, in a packet switched network for data communication, may employ a selection algorithm to determine the path over which data traffic is to be routed (i.e., stored and forwarded in multibit packet units). The illustration suggests choices available for multinode path selection. Traffic between host stations A and B is routed through the nodal exchange facilities a, b. If the "short" path currently presents three units of processing and transmission delay and the "longer" path (via nodal exchange facility c) encompasses six units of processing and transmission delay, it is more efficient to use the shorter path. However, when the shorter path is occupied to capacity the longer path must be used.

An option presently considered is to continually monitor path delays throughout the network and, when congestion on a short path appears imminent, reroute its traffic on a priority schedule by which that path is preferentially allocated to highest priority traffic; e.g., by routing all lower priority traffic, including low-priority traffic previously routed over the shorter path, to longer paths.

Highest priority may be assigned to control messages such as messages indicating instantaneous path delays in the network. By giving such preference to exchange of path delay information, the probability of "looping" or "ping- ponging" (due to unforeseen path occupancy) is reduced.

Obviously the ill...