Routing with partially disjoint shared path (PDSP) protection

We propose two algorithms for dynamic routing of guaranteed bandwidth pipes with shared protection that provide low blocking through thrifty resource usage. We assume that a single working path can be protected by one or multiple protection paths, which are partially or fully disjoint from the working path. This allows better capacity re-use (i.e., better capacity sharing among protection paths). Furthermore, the resources used by the paths affected by the failure, can be also re-used. The significance of the proposed method "PDSP-LD" is that we consider the amount of shareable protection capacity of each link, while determining the protection path for all affected demands simultaneously. Therefore it gives optimal routing of shared protection paths in case of any single link failure! The obtained results can be used for routing with protection in SDH/SONET, ATM, MPLS, WR-DWDM (including ASTN/GMPLS) and other networks.