Stability and Performance of Alternative Two-level Interconnection Networks

Packaging constraints motivate a two-level interconnection network for a multiprocessor. A single node in the global network contains multiple processors connected by a local network. An important issue in two-level networks is how alternative numbers of processors per node changes the per link traac in the global network. In the case of a hypercube global network we consider three communication schemes. We derive system stability conditions for each scheme under very general assumptions. Assuming the packets sent by a processor form a Poisson process, we also derive the worst-case mean end-to-end packet delay for the three schemes. We then use these results to compare alternative numbers of processors per node for the system size of a given multiprocessor.