Multicast support of a shared multi-buffer ATM switch with enhanced throughput in multicast environments

We propose a shared multi-buffer ATM switch, in which each unicast cell has chances to be read from a shared buffer during three consecutive read cycles and each multicast cell is read from a shared buffer if the shared buffer is not accessed for read of a unicast cell at the last read cycle. The HOL effect that the unicast cells experience is not augmented by the multicast cells and the utilization rate of the output ports is increased because both a unicast cell and a multicast cell have the opportunity to be read for each output port. For a fixed multicast rate, the proposed scheme shows a 98.9% throughput even though the offered load reaches 1. We designed the proposed shared multi-buffer ATM switch in 0.6 μm single-poly triple metal CMOS technology. The designed shared multi-buffer ATM switch has 8×8 ports and operates at 20 MHz, which supports a 155.52 Mbps STM-1 source rate for each port