Rerouting in connection-oriented communication networks and communication systems

Abstract

A Private Network-Network Interface (PNNI) network including interconnected nodes is defined as a single rerouting domain ('global domain') and the global domain is further defined by multiple divided domains ('local domains'). Each of the local domains is defined to include multiple nodes that are included in the network. Connection recovery and path optimization in the global domain (the entire PNNI network) are performed in accordance with a global rerouting protocol. The global rerouting protocol is a modification of the standard Domain-Based Rerouting (DBR) protocol, by adding information elements of domain identifier, rerouting for the global domain. The DBR protocol does not support the connection recovery from a link failure between local domains (“inter-domains”) and the global path optimization. The global rerouting method is capable of connection recovery and path optimization outside of any rerouting local domains. The global rerouting provides double fault recovery within the rerouting domain (“intra-domain”) as covered by the DBR and outside of the domains (“inter-domain”) or when the initial fault recovery within the domain has failed. Also, the global rerouting method provides maximum path optimization across all domains and within the rerouting local domain.