Efficient Broadcasting in Wormhole-Routed Multicomputers: A Network-Partitioning Approach

In this paper, a network-partitioning approach for one-to-all broadcasting on wormhole-routed networks is proposed. To broadcast 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 broadcast on the DDNs concurrently. Finally, a number of datacollecting networks (DCNs), which can work independently too, are constructed. Then concurrently on each DCN the sub-messages are collected and combined into the original message. Our approach, especially designed for wormhole-routed networks, is conceptually similar but fundamentally very different from the traditional approach (e.g., [4, 12, 17, 29]) of using multiple edge-disjoint spanning trees in parallel for broadcasting in store-and-forward networks. One interesting issue is on the definition of independent, in the sense of wormhole routing, DDNs and DCNs. We show how to apply this approach to tori, meshes, and hypercubes. Thorough analyses and comparisons 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 broadcasting algorithms.