A Delay-Constrained Shared Mesh Restoration Scheme

We present a multi-constrained routing algorithm, called delay-constrained pool sharing (DPS), in a survivable mesh network. The goal of this algorithm is to find a pair of link- disjoint primary and backup paths between a given source and destination nodes, which guarantees full recovery from any single link failure in the network. Our objective is to minimize the resources (such as backup bandwidth) used in the network as well as the total end-to-end delay time along the primary and backup paths. Our approach improves the end-to-end delay performance of the simple pool sharing (SPS) algorithm introduced in the literature, and proposes an integrated approach for quality of service (QoS) and resiliency. Using simulation, we studied the DPS algorithm on the existing North-American transport networks, and showed its improvements compared to the SPS scheme. We also introduce a hybrid algorithm which relaxes the delay constraint on the backup path in favor of maximizing the reusability (sharing) of the backup bandwidth.