Optimal Routing with Failure-Independent Path Protection

Reliable communication has become crucial in today's information society. Modern communication networks are required to deliver reliable communication to their customers. Unfortunately, protection against network failures significantly hampers efficient utilization of network investments, because the associated routing problems become much harder. In this article we present a rigorous mathematical analysis of one of the most promising protection methods: Failure independent path protection. We present an LP model which is solved by column generation. The subproblem is proven to be strongly \\cal NP-hard, but still solvable for medium sized networks through the use of specialized dynamic programming algorithms. This enables us to evaluate the performance of failure independent path protection for eight networks with up to 37 nodes and 57 links. The results indicate that only between 3% and 8% extra network capacity is necessary when compared with the capacity required by complete rerouting (which is the absolute lower bound for single link failure protection). © 2009 Wiley Periodicals, Inc. NETWORKS, 201

Optimal Routing with Single Backup Path Protection

Today's information society relies increasingly on advanced communication networks. This has lead to massive investments in increased communication network capacity. In order to utilize these investments the network operators perform traffic engineering, i.e., route communication in order to maximize the utilization of the capital invested in the communication network. Here we will consider traffic engineering of circuit switched networks where protection against single link failures is required