MULTISTAGE SHUFFLE NETWORKS WITH SHORTEST-PATH AND DEFLECTION ROUTINGFOR 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 intercon nection network built out of unbuffered b X 2b switching elements. Its structure is such that the number of cells that can be concurrently s witched from the inlets to each output queue equals the number of stag es 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. Th is paper presents the basic Shuffleout architecture, called Open-Loop Shuffleout, in which the cells that cross the whole interconnection ne twork without entering the addressed output queues are lost. A differe nt version of this architecture, called Closed-Loop Shuffleout, in whi ch cells are allowed to cross the interconnection network several time s before entering the appropriate output queue, is described in a comp anion paper [1]. The key target of the proposed architecture is coupli ng the implementation feasibility of a self-routing switch with the de sirable traffic performance typical of output queueing.