Efficient Algorithms and Routing Protocols for Handling Transient Single Node Failures

Single node failures represent more than 85% of all node failures in the today’s large communication networks such as the Internet [10]. Also, these node failures are usually transient. Consequently, having the routing paths globally recomputed does not pay off since the failed nodes recover fairly quickly, and the recomputed routing paths need to be discarded. Instead, we develop algorithms and protocols for dealing with such transient single node failures by suppressing the failure (instead of advertising it across the network), and route messages to the destination via alternate paths that do not use the failed node. This philosophy was also adopted in Ref. [14] where the authors address the same issues. We develop algorithms which are faster than those given in Ref. [14] by an order of magnitude, while our paths are equally good. We show via simulation results that our paths are usually within 9-12% of the optimal for randomly generated graph with 100-1000 nodes.