Shuffle Interconnection Networks with Deflection Routing for ATM Switching: the ClosedLoop ShuffleoutWork carried out at CEFRIEL, Milan (Italy), and supported by the Italian National Research Council in the frame of the Telecommunication Project.

A new class of switching architectures for broadband packet networks, called Shuffleout, is introduced in this paper. Its interconnection network is a multistage structure built out of unbuffered 2×4 switching elements. Shuffleout is basically an output-queued architecture in which the number of cells that can be concurrently switched from the inlets to each output queue equals the number of stages in the interconnection network. The switching element operates the cell self-routing adopting a shortest path algorithm which, in case of conflict for interstage links, is coupled with deflection routing. The architecture presented here is called Closed-Loop Shuffleout, since the cells that cross the whole interconnection network without entering the addressed output queues are lost. A different version of this architecture, called Open-Loop Shuffleout is described in a companion paper. The key target of the proposed architecture is coupling the implementation feasibility of a self-routing switch with the desirable traffic performance typical of output queueing.