8.3. End-to-End Dedicated Mesh Protection
End-to-end path protection and restoration refer to the recovery of an entire connection from the ingress to the egress port in a network. Suppose the working path of a connection is routed from a source NE A to a destination NE B through a set of intermediate NEs. In this and in the next section, we define end-to-end 1 + 1 protection modes, describe their functionality, and the signaling mechanisms needed to implement them.
8.3.1. Unidirectional 1 + 1 Protection
Under this protection mode, a dedicated, resource-disjoint alternate path is preestablished to protect the working path of the connection. Traffic is simultaneously sent on both paths and received from one of the functional paths by the end nodes ...