In-Transit Buers: A Mechanism to Support Minimal Routing in Myrinet

Due to the increasing computing power of microproces-sors and the high cost of multiprocessors, networks of work-stations (NOWs) are currently being considered as a cost-eective alternative for parallel computing. One of the pre-ferred network technologies for building NOWs is Myrinet [1], which provides simple and very exible network de-signs. In particular, it allows the network behavior to be changed through the Myrinet Control Program (MCP) exe-cuted by the LANai processor in the network interface card (NIC). Myrinet uses up*/down * routing [3] to build paths bet-ween network hosts. Unfortunately, up*/down * routing is not always able to provide a minimal path between some pairs of hosts, as shown in the following example. In Figur