Multicast ATM Switches Based on Input Cells Scheduling ∗

Multicasting has become an important part of current networking technologies. To accommodate the multicasting traffic, switches in ATM (Asynchronous Transfer Mode) networks need to be able to support multicasting. In multicast ATM switches, usually there are many cells contending for the same output port resources at the same time. This may lead to serious performance degradation. In the past, many special output port components are proposed to solve this problem. However, most of these approaches alleviate the output port overflowing problem without considering the output port congestion or the internal routing blocking problem. Especially when the switch fabric is based on the banyan-like network, these two problems will seriously degrade the switch performance. In this paper, we propose a pre-scheduling mechanism to precede the multicast switch. This mechanism will completely eliminate the problems mentioned above. Two architectures are designed to implement this mechanism. Analysis and simulations show that our design performs quite well. key words: ATM switch, multicasting, monotone sequence