Patent ID: 8103789

Claim:
A method comprising: determining a relationship between at least two links or at least two nodes in a network, where the relationship is determined based on the at least two links or the at least two nodes being associated with a common resource, where the relationship is based on a common characteristic or a common attribute that is indicative of the at least two links or the at least two nodes becoming inoperable when a single event related to the common resource occurs; assigning a cost associated with the at least two links or the at least two nodes based on the relationship and a likelihood that a failure of one of the at least two links or one of the at least two nodes, resulting from a failure of the common resource, will result in a failure of another one of the at least two links or the other at least two nodes; and determining, based on the assigned cost, a primary path and a backup path through the network, the primary path including the one of the at least two links or the one of the at least two nodes and the backup path including the other one of the at least two links or the other one of the at least two nodes.