Nortel Networks Corporation

Ciena Luxembourg S.a.r.l.

De Boer, Evert E.

Evert E De Boer

James A Shields

Richard Trudel

Darryl C Ryan

In a mesh network, a network element for providing protection switching in a 1:N shared mesh protection scheme having a first protection path associated with a pair of working paths selected from the N working paths is disclosed. The network element comprising: (a) a link for connecting the network element to a first working path of the pair of working paths in a path layer of the network, the path layer including a plurality of interconnected network elements; (b) a routing table accessible by the network element, the routing table for having local protection channel information associated with a local protection segment separate from the first protection path, the local protection segment connecting the network element and one of the interconnected network elements adjacent to the network element; and (c) an identification module for using the local protection channel information to identify an available protection channel on the local protection segment in the event of failure of a local working segment of the first working path, the local working segment connecting the network element and said one of the adjacent interconnected network elements; wherein the available local protection channel on the local protection segment is used to switch local network bandwidth from the failed local working segment to the local protection segment after the failure has been detected. Selection functions are also disclosed.

Shared mesh signaling method and apparatus

A shared mesh protection scheme defines an associated protection path when a working connection is established. During the protection path definition, the corresponding protection path information is sent down to a switch card of network elements making up the protection path. Upon detection of the failure, the network elements using an overhead byte message will inform the routing source network element of the connection of the failure in the working path. The overhead bytes used are interrupt driven bytes located in the line and path overhead of network traffic. The routing source node of the connection will then send the corresponding overhead byte messages down the protection path to provide for protection path establishment according to the preloaded data located at the switch card. It should be noted that each connection can have a source and termination element which relates to the source from where the corresponding connection was set-up rather than the direction of the payload transmission. Therefore, once the failure has occurred the source elements will send messages using overhead bytes to the corresponding network elements along the protection path. Accordingly, routing tables located at the switch card of the network elements, set-up when the working path connections were initially established, determine this dynamically allocated protection path environment.

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Nepean, Canada

Evert E De Boer