A directory enabled solution for MPλS path protection and restoration

It is very important that the large amount of traffic carried by optical channels is protected against potential failures in the network. The MPλS recovery approaches can be classified as local recovery or global recovery. In case of local recovery, the switch over to recovery path is performed by the O-LSR that is immediately upstream of the point of failure, whereas in case of global recovery, the switch over is performed by a predetermined O-LSR known as the O-protection switch LSR (O-PSL). The failure notification plays an important role in the global recovery approach, as the O-PSL has to be notified about the failure in order for the recovery procedure to be initiated. This paper proposes the use of a directory service as part of the global MPλS recovery framework. The proposed architecture enables fast and effective notification of MPλS O-LSP failures, which facilitates quick recovery to the backup O-LSPs. The proposed architecture also scales effectively to all O-LSPs affected by the failure and promotes improved utilization of network resources by greatly reducing the involvement of the O-LSRs in MPλS path protection and restoration.