Resolving conflicting topology information

Abstract

A topology manager external to a communications network manages the network and in particular resolves conflicting topology information about the network by dividing the management of the topology data base into two operations--a collection instance and a resolution layer. A collection instance collects all information that its agent node has about the topology of the network. This topology information is processed by the collection instance to determine for each resource in the network whether the resource is new, reachable or has experienced a reachability change. The resolution layer receives the topology resource information from each collection instance. When a resource is indicated as reachable by a collection instance, that resource is placed on a Reach list as an entry from that collection instance. If the collection instance indicates the resource from that collection instance is no longer reachable, the resolution layer will remove that resource entry from the Reach list, and look for another Best Reach entry for the resource. If the network fragments and nodes go down and come back up, the resolution layer can resolve conflicts in resource information from separate collection instances to select the most current information for a resource.