Patent ID: 8233387
Filing Date: 2012-07-31
Classification: H04L

Abstract:
1. A method performed on a network element implementing Multiprotocol Label Switching (MPLS) to automatically create an optimal deterministic back-up Label Switch Path (LSP) that is maximally disjointed from a primary LSP to provide a reliable back up to the primary LSP, the method comprising the steps of: receiving a request for a generation of an LSP by the network element via a signaling protocol; determining that the request for the generation of the LSP is for the back-up LSP; locating each link of the primary LSP in a traffic engineering database in response to determining that the request is for the back-up LSP; modifying each link of the primary LSP in the traffic engineering database to have a link cost other than an actual link cost to discourage use of each link of the primary LSP in the back-up LSP; executing a Constrained Shortest Path First (CSPF) algorithm on the traffic engineering database to obtain the back-up LSP, wherein the back-up LSP has a maximum disjointedness from the primary LSP due to a modified cost of each link of the primary LSP in the traffic engineering database; returning the back-up LSP via the signaling protocol; and restoring a cost value for each link of the primary LSP in the traffic engineering database to have an original cost after the back-up LSP is determined.