An Eecient Fault-tolerant Routing Scheme for Two Dimensional Meshes

Most of the previously proposed fault-tolerant wormhole routing algorithms for direct networks are extensions of the existing adaptive routing algorithms. These extensions are usually done by adding extra virtual channels to the network. Since these additional virtual channels are used for the fault tolerance purposes , they are not eeciently utilized when there are no faults in the network. In this paper, we propose a new fault-tolerant routing scheme for 2-dimensional mesh networks. It provides alternate physical paths to a message until it reaches the last dimension. While routing in the last dimension, if the message encounters a faulty node, it is stored completely at the adjacent node and is retransmitted. Using this routing scheme no adaptivity is sacriiced when there are no faults in the network and no additional virtual channels are required for fault tolerance. The performance of the proposed scheme is better than the previously proposed fcube algorithm which uses the same number of virtual channels. The eeect of number and location of faults on the latency and the utilization is also studied.