Survivable Routing of Unicast and Anycast Flows in MPLS Networks

Most of previous research in anycasting has been focused on best-effort networks and IP networks. In contrast, we propose a QoS-based routing of anycast demands in connection-oriented MPLS network. Since in real networks different kinds of flows are transmitted over the same links, we assume that both unicast and anycast requests must be served in the network. Survivability of the network is one of the most important elements of QoS parameters since network failures can lead to significant consequences. We examine performance of several constraint-based algorithms for anycast server selection and QoS unicast routing algorithms. As the performance metric we use the flow lost due to a single failure of the link. For network restoration of anycast flows we propose a new scheme called backup server. Simulations show that application of backup server approach can significantly improve the network survivability.