US 5,940,396 AGranted

Method of routing in an asynchronous transfer mode network

Assignee3Com Corporation

InventorHaim Rochberger

Life of this patent

Estimating the term…

Loading patent…

Abstract

A novel method of routing and performing autoconfiguration in an ATM network is disclosed. The method simplifies the configuration and routing for ATM networks having a relatively large number of nodes. Networks are constructed in hierarchical fashion in the form of branches and trees and assigned network address prefixes in accordance with their location in the network. Network nodes periodically exchange identification information permitting both switches on either side of a link to be aware of who they are connected to. Each node registers a network address and its associated significant length for each of its neighbors on each of its links. A node performs routing by comparing the destination address against each of its registered addresses for all its links. The routing method takes advantage of the network address prefix to ensure that the routing proceeds in the correct direction towards the destination and does not enter a tree or a branch that does not contain the destination. In addition, each node performs load balancing at each point in the routing process. A node can generate crankback messages if the routing leads to a dead end.

Claims18

Dependent claims

A method of routing in an Asynchronous Transfer Mode (ATM) network, said network including a plurality of nodes, each said node having one or more ports and possibly connected to one or more users through a first type link, said nodes connected to each other through a second type link, said network including a source node connected to a source user and a destination node connected to a destination user having a destination address, said source user generating a SETUP message containing said destination address, each node having a network address comprising a network prefix and a significant length, said method comprising the steps of:

constructing said network in hierarchical fashion out of one or more trees, each said tree having a root such that said trees are connected in a mesh at their roots;
exchanging identification messages between said nodes across each of said links on each node (termed the current node) in the routing path;
making a first determination of whether said destination address matches the network address of a user connected to said current node through said first type link;
outputting said SETUP message to a port in accordance with said first determination if said first determination is true;
making a second determination of whether said destination address fully matches the network address of a node connected to said current node through said second type link;
outputting said SETUP message to a port in accordance with said second determination if said second determination is true;
making a third determination of whether said destination address partially matches the network address of a node connected to said current node through said second type link;
outputting said SETUP message to a port in accordance with said third determination if said third determination is true;
and
outputting said SETUP message onto a default port.

7 more elements

A method of routing in an Asynchronous Transfer Mode (,ATM) network, said network including a plurality of nodes, said nodes connected to each other by one more links, said network including a source node connected to a source user and a destination node connected to a destination user, said source and said destination user connected to said source node and said destination node, respectively, each node having a network address comprising a network prefix and a significant length, said method comprising the steps of:

on each node, termed the current node, in the routing path;
making a first determination of whether said destination address matches the network address of a user connected to said current node through said first type link;
outputting said SETUP message to a port in accordance with said first determination if said first determination is true;
making a second determination of whether said destination address fully matches the network address of a node connected to said current node through said second type link;
outputting said SETUP message to a port in accordance with said second determination if said second determination is true;
making a third determination of whether said destination address partially matches the network address of a node connected to said current node through said second type link;
outputting said SETUP message to a port in accordance with said third determination if said third determination is true;
and
outputting said SETUP message onto a default port.

6 more elements

Dependencies are inferred from the claim text.