Diverse routing in WDM optical networks with shared risk link group (SRLG) failures

We study the diverse routing problem in WDM optical networks with SRLG failures. We consider a more general case of SRLG failures than those considered in Datta and Somani (2004) and Doucette and Grover (2002). All the optical links in an SRLG share a common endpoint. In addition, a link can belong to arbitrary number of SRLG groups and an SRLG may include more than two links. We develop a polynomial time optimal algorithm to find a pair of least cost SRLG-disjoint paths between a source and a destination. We prove the correctness of the algorithm which is also shown to be more time efficient than the graph transformation based algorithm of Datta and Somani (2004).