Restoration methods for traffic engineered networks with loop-free routing guarantees

Link-state protocols such as open shortest path first (OSPF) are the dominant routing technology in IP networks. Previous work has addressed the ability of OSPF to make smart routing decisions based on network configuration and bandwidth demand. Traffic engineered networks that make use of this enhanced routing will experience loops in the case of link failure. This paper presents an algorithm that solves the loop problem in the event of a link failure or a severely congested link. Upon a link failure, the algorithm will build a restoration path that will reroute traffic as well as notify neighboring routers of the link failure. The informed routers will make intelligent forwarding decisions based on past and present arc weights. All routers will be informed of the failure, building a restoration network and leading to the new network topology and arc weights.