A fast link failure recovery technique based on Multi-Topology

With the rapid development of Internet, it has become an essential infrastructure for communication today, while the IP layer has a poor ability in fast failure recovery, which impending the improving of the Internet performance. Concerned to the single link failure problems, this paper proposed a fast link failure recovery mechanism based on multi-topology. Firstly, by theoretical analysis, the number of the backup topology was determined with up to 3; Secondly, we also proposed to create the smallest similarity graphs as the backup topologies which is based on link vector similarity so than the router can switch to the backup link computed in advance to protect the failure in real time. Simulation results show that the shortest average path length obtained by our Multi-Topology(MT) algorithm has little difference with the Dijkstra algorithm, but is less than FIR(Failure Insensitive Routing), which exhibits a good performance. In addition, with the increasing of node degree, mathematical expectation and variance of the shortest average path difference between MT and Dijkstra remains a very small range that can be ignored.