Multicast switch based on tandem expanded delta network

High speed networking applications like video-on-demand require the support of switches which can handle very high multicast loads. B-ISDN switches with multicasting capabilities can be used to support such applications efficiently. These switches must be fast and the routing delays for the packets must be small. The switches studied in the literature can support multicast loads (ratio of number of multicast packets to total number of packets) of 25-30%; without much degradation in performance. But, for higher loads, the delays of the packets can be very large. We describe a new design for a switch which can withstand multicast loads of 85-90% without a loss in performance. The switch has very low latency, small packet routing delay and minimal buffering. These features make the switch an attractive component for future high-speed networks.