Patent ID: 7061921
Filing Date: 2006-06-13
Classification: H04L

Abstract:
1. A communications system, comprising: a first label switching router configured to operate as an ingress router for a first label switched path and as an egress router for a second label switched path, the first label switching router including information associating the first and second label switched paths to implement a logical signal interface; a second label switching router configured to operate as an ingress router for the second label switched path and as an egress router for the first label switched path, the second label switching router including information associating the first and second label switched paths, the second router further being configured to operate as a penultimate router for a third unidirectional label switched path which is not part of a bi-directional logical switched interface between the end points of said third unidirectional label switched path, said second router being configured to use a null label when forwarding packets corresponding to the third unidirectional label switched path; and a third label switching router, the third label switching router being configured to operate as a penultimate router in said first label switched path, said third label switched router being configured to include a non-null label with packets corresponding to said first label switched path when said packets are forwarded along said first label switched path to the second label switched router which operates as the egress router for said first label switched path.