MULTISTAGE SHUFFLE NETWORKS WITH SHORTEST-PATH AND DEFLECTION ROUTING FOR HIGH-PERFORMANCE ATM SWITCHING - THE OPEN-LOOP SHUFFLEOUT

A new class of switching architectures for broadband packet networks, called Shuffleout, is described and analyzed in this paper. Shuffleout is basically an output-queued architecture with a multistage interconnection network built out of unbuffered b X 2b switching elements. Its structure is such that 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. This paper presents the basic Shuffleout architecture, called Open-Loop Shuffleout, in which the cells that cross the whole interconnection network without entering the addressed output queues are lost. A different version of this architecture, called Closed-Loop Shuffleout, in which cells are allowed to cross the interconnection network several times before entering the appropriate output queue, is described in a companion paper [1]. 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.