Inventors:
Dan Cedrone - Groton MA
Walter Dray - Carlisle MA
Ed Klein - Holliston MA
James Regan - Waltham MA
Bappa Sinha - Brighton MA
Ming-Teh Ma - Newton MA
Jeffrey Weiss - Lincoln RI
Assignee:
Ciena Corporation - Linthicum MD
International Classification:
G01R 3108
US Classification:
370216, 370222, 370223, 3702411
Abstract:
A system with predefined primary and secondary routes sets up corresponding virtual circuits over both routes. A destination node maintains primary and secondary sets of routing tables that contain, respectively, routing information over each of the rings for every virtual circuit. A destination node disables the appropriate entries in the routing tables for the non-selected route, such that the node ultimately discards the traffic received over that route. To switch a virtual path, and thus all of the virtual circuits included therein, from the selected route to the nonselected route, the destination node disables and enables the appropriate entries in the primary and the secondary routing tables, to switch from using the set-up virtual circuits on the selected route to using the set-up virtual circuits on the non-selected route. To detect an event that triggers protection switching, such as path failure, the system uses âContinuity OAM cellsâ to provide path status information to the nodes. A source node periodically originates Continuity OAM cells over the primary and the secondary routes.