Distributed routing schemes for strictly nonblocking networks

Abstract

Strictly nonblocking networks may hold the key for high performance multiprocessor systems. While a number of strictly nonblocking networks have been reported in the literature, their use in multiprocessors is hampered by a lack of efficient distributed routing at algorithms to set paths in these networks. As a step in this direction, the paper presents two distributed routing algorithms for D.G. Cantor's (1971) strictly nonblocking network. For N inputs, the first routing algorithm takes O(t)+O(logt log N) steps/sup 1/ to routing t requests in parallel. While this algorithm performs quite well for i=O(log/sup 2/ N), for larger valves of t, we present a randomized version of the same algorithm with an expected time complexity of O(log/sup 2/ N) for any number of requests. These results, when combined with the crosspoints and depth complexities of a Cantor network, give a strictly nonblocking network with O(N log/sup 2/ N) crosspoints, O(logN) depth and O(log/sup 2/N) routing time.