A rearrangeable network is an interconnection network which can achieve all possible permutations of its inputs' connections to its outputs. One class of rearrangeable networks, which have been studied are Clos three-stage networks. Earlier procedures to route such networks rapidly require an excessive amount of hardware, either in the network itself or in the device required to compute the routing. A class of rearrangeable three-stage networks which is both compact and which can be routed quickly is introduced, along with a routing scheme. Switches are added to the network so as to reduce the interdependence between the switch settings, allowing faster routing while only moderately increasing network complexity. A network with O(Nlog/sup 1.5/N) hardware and O(log/sup 1.5/N) depth is derived from O(log/sup 2.5/N) switch setup time.>

A self-routing connection network is a switching device where the routing of each switch can be determined in terms of the destination addresses of its inputs alone, i.e. independent of the routing information regarding the other switches in the network. One family of connection networks that were considered in the literature for self-routing are Clos networks. Earlier studies indicate that some Clos networks can be self-routed for certain permutations. In this paper, it is proved that the only category of Clos networks that can be self-routed for all permutations are those with at most two switches in their outer stages.>