PATH PROTECTION SCHEME IN A SHARED MESH NETWORK

摘要

A shared mesh protection scheme defines an associated protection path when a working connection is established. Both global and local protection schemes are used to provide advantages similar to ring and span protection switching in ring networks. During the global 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 failur e, 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. Accordingly, the routing tables located at the switch cards of the network elements, set-up when the working path connections were initially established, determine this dynamically allocated protection path environment. It is noted that interrupt driven overhead byte s for network traffic are used to help provide for protection times of less th an 300 msec. Local protection switching and switch selection on available local protection segments can be used instead of the global protection scheme when local protection channels are available on the local protection segments.