Patent ID: 7561534
Filing Date: 2009-07-14
Classification: H04L

Abstract:
1. A method of determining a first primary path and a first backup path for routing information in a physical network of connection nodes connected by links, the method comprising: defining a graph G to represent the physical network with nodes of the graph G representing connection nodes of the physical network and edges of the graph G representing links of the physical network; assigning shared risk of link failure costs to a plurality of the edges of the graph G; identifying a first path from a first node of the network to a second node of the network based on the graph G with the assigned shared risk of link failure costs; and identifying a second path from the first node of the network to the second node of the network based on a reduced edge residual graph, wherein a reduced edge residual graph is formed by removal of edges from the graph G that share a risk of failure with an edge of the first path, wherein edges on the first path from the second node to the first node are excluded from being removed.