The shuffle/exchange-plus networks

Abstract

From the reliability point of view, the uniqueness of path between any processor and memory module in a standard k-column Shuffle/Exchange (S/E) network is an inherent weakness. It is proposed to add a column of switches to the existing multistage S/E network such that the modified network, which will be called the S/E-Plus network, will retain the permuting power of the corresponding S/E network and have dual paths between any processor and any memory module. Fault tolerant routing algorithm is then designed to exploit the dual path structure of the S/E-Plus network. Various applications of the routing algorithm including a technique for performing permutation in the S/E-Plus network in which a fault exists are also discussed. Finally, the path reliability and the path reliability gain are defined to evaluate the S/E-Plus network.