Tree-based Multicasting on Wormhole Routed Multistage Interconnection Networks 1

Multicast operation is an important operation in multicomputer communication systems and can be used to support several other collective communication operations. A signi cant performance improvement can be achieved by supporting multicast operations at the hardware level. In this paper, we propose a tree based multicasting algorithm for Multistage Interconnection Networks (MIN). We rst analyze the necessary conditions for deadlocks in MINs. Based on these observations, an asynchronous tree-based multicasting (ATBM) algorithm is developed in which deadlocks are prevented by restricting the number of tree operations using a grouping technique for the switching elements. The ATBM approach is not only simple to implement but also provides good communication performance using minimal overheads. The performance of the ATBM scheme is evaluated through simulation experiments. The preliminary results are encouraging at it lowers the latency by almost a factor of 4 when compared with the software multicasting approach proposed earlier.