Fairness in a broadband packet switch

A Batcher-banyan interconnection network and a three-phase algorithm to resolve the output channel contention are discussed. For the implementation of the sorting network the author proposes two alternative solutions that aim at providing a fair access to the output channels independent of the specific switch input port requesting the transmission bandwidth. The first uses two complementary Batcher networks. The second adopts a preprocessing of the jobs entering the interconnection network, so that each input port is cyclically served first within the set of input ports requesting the same output channel with the same priority. The general architecture of the interconnection network is described, and implementation guidelines are discussed