Patent ID: 8194535
Filing Date: 2012-06-05
Classification: H04L

Abstract:
1. A computer-implemented method for supporting recovery from failure of a node in a network of nodes interconnected by links, wherein the failed node is in a path providing a service level between an ingress point and an egress point of the network, the method comprising: (a) the computer selecting a set of two or more intermediate nodes between the ingress point and the egress point, the set excluding the failed node; (b) the computer determining, based on available bandwidth of the network, a non-zero fraction of the service level to route from the ingress point to each intermediate node; (c) the computer implementing, during a first routing phase, a first routing method to determine one or more paths from the ingress point to each intermediate node for routing the corresponding fraction of the service level; and (d) the computer implementing, during a second routing phase, a second routing method to determine one or more paths from each intermediate node to the egress point for routing the corresponding fraction of the service level, wherein the determination of the non-zero fraction of the service level to route from the ingress point to each intermediate node is made by solving a linear program having primal and dual solutions, wherein flows along the links are augmented in the primal solution, and weights of the links are updated in a multiplicative fashion in the dual solution.