Method and system for network topology updating using topology perturbation

An iterative method for configuring a communication network includes the steps of identifying a given network configuration having a given network topology based on arcs having associated administrative routing weights and including a number of given shortest paths, generating at least one neighbouring configuration by producing in the network topology a perturbation leaving administrative routing weights unaffected and wherein the majority of the shortest paths in the neighbouring configuration have shortest paths from the number left unaffected by the perturbation and combinations of shortest paths from said number, evaluating the neighbouring configuration against the given configuration based on a given cost function, whereby the evaluation involves only the portion of the network topology affected by the perturbation, and substituting the neighbouring configuration for the given configuration if the neighbouring configuration is found to represent an improvement over the given configuration based on the cost function.