Performance studies of a selfhealing network protocol in Telecom Canada long haul networks

Telecom Canada commissioned a study to verify the speed and routing performance of a newly developed self-healing network (SHN) restoration technique. The particular SHN protocol is based on a unique paradigm for rapid, distributed, physical-layer interaction among digital cross-connect system (DCS) machines. An implementation of the protocol, as it would be installed in a DCS machine, was executed concurrently in every node of models of the Canadian transcontinental network, using an asynchronous network emulator. Results from nearly 1800 span-cutting experiments in networks of up to 93 nodes, 157 spans, and 6000 DS-3s showed that the protocol reliably performs multiple successively shortest paths rerouting of whole cable cuts in under 2.5 s, and acts like a conventional span protection switching system in about 40 ms. Restoration behaviour with multiple simultaneous faults and time concatenated faults has also been verified