METHOD AND APPARATUS FOR SIMPLIFYING THE COMPUTATION OF ALTERNATE NETWORK PATHS

An alternate path calculation process may be terminated after considering some of a source node's neighbors and without considering each of its neighbors, to reduce the amount of processing required to perform the alternate path calculations. The neighbors may be ranked according to the number of alternate paths that the neighbor has historically been able to provide on the network. The influence of historical success or failure may degrade over time so that the rankings may be adjusted to reflect changes in network topography. A given source node, when computing alternate paths through the network, may preferentially select neighbors to perform alternate path calculations on historically higher scoring nodes before performing calculations on historically lower scoring nodes. Several different criteria may be used to stop the alternate path calculation process before considering all neighbors. The neighbors may be loop free neighbors or U-turn neighbors.