Patent ID: 7388828
Filing Date: 2008-06-17
Classification: H04L

Abstract:
1. A method for protecting packets of MPLS traffic in ring networks comprising a ring having a plurality of nodes, in case when a section extending between at least two nodes of said ring becomes faulty, wherein the MPLS traffic comprises two or more Label Switched Paths (LSPs) entitled to protection, and wherein each of said packets carries an original label corresponding to a specific LSP, the method comprising: at a first edge node bordering the faulty section, redirecting the MPLS traffic in the opposite direction along the ring, via a shared protection path; when being redirected to the protection path at the first edge node, providing each of the redirected packets with an additional, outer label to its label stack, said additional label indicating the fact that the packet is carried along the protection path; recognizing the packets belonging to the redirected MPLS traffic by detecting, at the protection path nodes presence of said additional label; for each packet arriving at a particular node along said protection path and recognized as belonging to the redirected MPLS traffic by detecting said additional label, determining whether the particular node is the packet's egress point from the ring, said determining being performed depending on arrangement of the protection path: the method then comprises allowing egress of said packet of the redirected MPLS traffic from the ring at said particular node, if said particular node is either the termination point of the mptp path or the packet's egress node from the ptp or mptmp protection path, forwarding said packet of the redirect MPLS traffic to a next node along the ring, said particular node is neither the termination point of the mptp protection path nor the packet's egress node from the ptp or mptmp protection path.