Efficient Tree-Based Multicast in Wormhole-Routed Networks

This paper presents two tree-based multicast algorithms for wormhole-routed nD torus and 2D mesh networks, respectively. Both of the two algorithms use multiple spanning trees with an up-down routing strategy to provide deadlock-free routing. In contrast with single spanning tree algorithms that use non-tree links only as shortcuts, the presented algorithms use all links (for nD tori, all but n links) as tree links and, therefore, better balance network traffic and resource utilization. For the algorithm in 2D mesh networks, shortcuts can still be used to shorten routing path for both unicast and multicast messages. Simulation results show that both of the proposed algorithms outperform the best single spanning tree approach obviously.