A Light-weight fault-tolerant routing algorithm tolerating faulty links and routers

Faults at either the link or router level may result in the failure of the system. Fault-tolerant routing algorithms attempt to tolerate faults by rerouting packets around the faulty region. This rerouting would be at the cost of significant performance loss. The proposed algorithm in this paper is able to tolerate both faulty routers and links with negligible impact on the performance. In fact, the proposed algorithm avoids taking unnecessary longer paths and the shortest paths are always taken as long as a path exists. On the other hand, fault-tolerant routing algorithms might be based on deterministic routing in which all packets use a single path between each pair of source and destination routers. Using deterministic routing, packets reach the destination in the same order they have been delivered from the source so that no reordering buffer is needed at the destination. For improving the performance, fault-tolerant algorithms might be based on adaptive routing in which packets are delivered through multiple paths to destinations. In this case, packets should be reordered at the destinations demanding reordering buffers. The proposed algorithm can be configured in both working modes, such that it can be based on deterministic or adaptive routing.