Design and implementation of Abacus switch: a scalable multicast ATM switch

This paper describes a new architecture for a multicast ATM switch scalable from a few tens to a few thousands of input ports. The switch, called the Abacus switch, has a nonblocking switch fabric followed by small switch modules at the output ports and buffers at input and output ports. A novel algorithm has been proposed to resolve output port contention while achieving input buffer sharing, fairness among the input ports, and call splitting for multicasting. The channel grouping mechanism is also adopted in the switch to reduce the hardware complexity and improve the switch´s throughput, while the cell sequence integrity is preserved. A key component for building the Abacus switch, the ATM routing and contention (ARC) chip has been implemented with CMOS 0.8-μm technology and tested to operate correctly at 240 Mbit/s. The performance study of the Abacus switch in terms of the throughput, average cell delay, and cell loss rate is also presented