Fault-tolerant broadcasting in wormhole-routed torus networks

This paper describes a fault-tolerant broadcast algorithm for wormhole-routed torus networks for which there is only local knowledge of faulty components. This algorithm tolerates tip to k-1 faulty nodes in a k-ary n-cube provided the faults do not cause the network to be disconnected. Based on the fault-tolerant dimension-order unicast communication, this algorithm is deadlock-free and no additional virtual channels are needed. The first stage of this algorithm is itself an optimal broadcast algorithm for a torus if no faults are present. The second stage overcomes the presence of up to k-1 faults with a fixed number of additional message transmissions. Thus, the cost of this algorithm is within a constant factor of the cost of optimal non-fault-tolerant broadcast algorithms.