Efficient Multicast in Wormhole-Routed 2D Mesh/Torus Multicomputers: A Network-Partitioning Approach

In this paper, a network-partitioning scheme for multicasting on wormhole-routed networks is proposed. To multicast a message, the scheme works in three phases. First, a number of data-distributing networks (DDNs), which can work independently, are constructed. Then the message is evenly divided into sub-messages each being sent to a representative node in one DDN. Second, the sub-messages are multicast on the DDNs concurrently. Finally, a number of data-collecting networks (DCNs), which can work independently too, are constructed. Then concurrently on each DCN the sub-messages are re-collected and combined into the original message. One interesting issue is on the definition of independent DDNs and DCNs, in the sense of wormhole routing. We show how to apply this scheme to 2D tori and meshes. Thorough analyses and experiments based on different system parameters and configurations are conducted. The results do confirm the advantage of our scheme, under various system parameters and conditions, over other existing multicasting algorithms.