Hierarchical multistage interconnection network R-Clos

This paper proposes the multistage interconnection network (MIN) R-Clos, with a hierarchical structure in which locality of communications can be utilized. In R-Clos, a Clos network, which is a three-stage MIN, is used as the local network. By interconnecting multiple Clos networks through the intermediate stage of the hierarchical structure, a large-scale system can be constructed with a smaller hardware requirement than that for a Clos network. On the other hand, due to the use of the Clos network, with great transfer power, as the network for nearby data communications, low latency and wide bandwidth can be provided for nearby access. The latency and throughput of the proposed configuration are evaluated by a simulation using a stochastic model. Although the performance is lowered for traffic with a uniform access pattern, the transfer performance is improved for a data distribution with high locality, compared to the recursive (2s - 1)-stage Clos.