A modular architecture for very large packet switches

Switch modules, the building blocks of this system, are independently operated packet switches. Each module consists of a Batcher sorting network, a stack of binary trees, and a bundle of banyan networks. The modular architecture is a unification of the Batcher-banyan switch and the knockout switch, and can be physically realized as an array of three-dimensional parallel processors. Switch modules are interconnected only at the outputs by multiplexers. The partitioned switch fabric provides a flexible distributed architecture, which is the key to simplify the operation and maintenance of the whole switching system. The modularity implies less stringent synchronization requirements and makes higher-speed implementation possible. The proposed modular switch is intended to meet the needs of broadband telephone offices of all sizes. It is estimated that a modular switch with terabit capacity can be built using current VLSI technologies