Extension of the k-SPF algorithm for finding SRLG-disjoint primary and backup route pairs in optical networks

There is a strong demand for creating primary/backup optical path pairs between a source and a destination node in order to continue a service when the primary path has some disorder. We also have to consider SRLG (shared risk link group)-disjoint primary/backup path settings for achieving robust path protection against possible network problems on primary paths. To deal with these issues, in this study, we use the k-SPF (shortest path first) algorithm to determine primary/backup path routes between a specified source/destination node pair. We demonstrate that the proposed algorithm can find $k$ SRLG-disjoint primary/backup route pairs with much higher probability and with faster speed compared with other algorithms. In addition, the proposed algorithm can find primary/backup routes with nearly minimum route costs.