Routing method for setting up a service between an origination node and a destination node in a connection-communications network

Abstract

A setup procedure employing distributed hop-by-hop routing reduces the number of signaling messages needed to establish a service (i.e., connection), thus enhancing network performance. A service is setup between an origination node and a destination node which are a part of a network of communication nodes interconnected by links. Each node maintains a topological database representing the network topology. Initially, a setup message for initiating the service is transmitted from the origination node to a neighboring node that serves as a local node. The topological database is then updated after the local node receives the setup message by eliminating links connected to a particular set of nodes. This set of nodes includes those nodes other than the local node that have previously transmitted a setup or failure message for the service. A shortest path is next determined from the local node to the destination node over the updated topology and another setup message is transmitted from the local node to a first neighboring node in the shortest path. The previously-mentioned steps are repeated, beginning with the step of updating the topological database, where the neighboring node now serves as a subsequent local node. The steps are repeated until either a setup message reaches the destination node so that the service enters a connected state or no shortest path is found at the origination node, which indicates that the service has failed to enter a connected state.

Dependencies are inferred from the claim text.