Patent ID: 8611232

Claim:
A method for balancing load in a network after failure of a link, the network comprising a plurality of interconnected vertices and edges and a set of traffic demands, each demand defining a flow requirement from an ingress router to an egress router, the network further comprising a set of failure states, the method comprising: at the ingress router, routing traffic by automatically balancing traffic load over a predefined set of paths from the ingress router to the egress router according to a set of splitting ratios, each splitting ratio defining a fraction of the demands to be transmitted over a path of the predefined set of paths in a case of a detectable failure state corresponding to a subset of a modeled set of the failure states, the modeled set of the failure states being states that cause at least one path of the predefined set of paths to fail, the modeled set of the failure states including a no-failure state in which the network has no failures, each modeled failure state having a predetermined probability of occurrence; and in an off-line management system, pre-computing the predefined paths and the splitting ratios, wherein pre-computing the splitting ratios further comprises solving a linear program having an objective function defining congestion over the modeled set of the failure states, the objective function including a factor comprising a sum of weights for each of the modeled set of the failure states to emphasize common failure states.