PNNI-BASED MULTI-LINK SHORTEST PATH CLASS-OF SERVICE ROUTING

摘要

The present invention concerns a technique for providing Class-of-Servi ce Routing in an ATM network (10) that utilizes the Private Network-Network Interface (PNNI) protocol. An originating node seeking to route a call to a terminatin g node does so by initially selecting a shortest length path therebetween. Each successi ve link on the selected path is examined for sufficient available bandwidth for the Class-o f- Service of the call. If every link possesses sufficient available bandwidth, then the call passes on the selected path. Otherwise, should a link on the selected path lack sufficient bandwidth, then a crankback message is sent to the originating node, and the originatin g node selects the next shortest path. Thereafter, the process of examining each link for sufficient bandwidth is repeated. If no path is found, the call is ultimately blocked.< /SDOAB>