A modular, 160 Gbps ATM switch architecture for multimedia networking support, based on a 3-stage Clos network

In this paper, we propose an ATM switch architecture with a nonblocking switching capacity scalable to 160 Gbps. This switch is appropriate for backbone broadband switching of multimedia and video-on-demand applications, where high switching capacity is required. The switching fabric consists of a number of modular switching elements, interconnected in a 3-stage Clos network, with a total number of up to 1024 input ports and 1024 output ports (OC-3). Each switching element of the network consists of up to eight 4 x 4 switching modules, interconnected via a common bus. Internally, each module performs both input and output queuing. Cells are switched through a. shared local bus. Fast arbitration logic is used to control the various busses of the network. Although there is shared resource contention, the proposed architecture can be nonblocking, if the internal bus operation is adequately fast. Simulation results show that nonblocking operation is feasible, with total internal buffering of as small as 18432 cells, achieving cell latencies of as lear as 6 to 10 mu sec. Given the appropriate Call Admission Control algorithm and an adequate number of middle-stage switches, the Clos network call also provide nonblocking operation at call setup.