Method of combining PNNI and E-IISP in an asynchronous transfer mode network

Abstract

A method of permitting older networks based on E-IISP routing to operate in newer PNNI based networks. The invention combines the PNNI and E-IISP routing schemes and permits their simultaneous execution in the same ATM network. The E-IISP routing scheme is modified so as to operate in unison with the minimal PNNI implementation configured on each node. The Hello protocol and associated Finite State Machine (FSM) are utilized to determine whether a remote node is in the same peer group. If it is determined that both nodes are in the same peer group, the ports on either side of the link are configured as standard PNNI type ports. If it is determined that the two nodes are from different peer groups, the ports on either of the link are configured as E-IISP type ports. Foreign address information is then exchanged between the two nodes thus permitting border nodes to learn about other peer groups from their respective remote nodes. Relatively large networks can be constructed that do not have any hierarchy as in networks running the full PNNI standard. Via the Hello protocol, changes made to links between nodes will be detected immediately and the port configuration modified appropriately.

Dependencies are inferred from the claim text.