A crossbar ATM switch for multicast traffic

A crossbar ATM switch for multicast traffic is proposed. First, we propose a crossbar ATM switch to which is added a new state of a switch element capable of performing cell replication at the routing crossbar, with a header translator placed in front of the concentrator following the routing crossbar, as the proposed model 1. By adding minimal faculties to the conventional model, proposed model 1 can cope with multicast traffic without degrading the performance of the conventional model. However, due to treatment of multicast traffic in proposed model 1, output congestion is liable to occur. Furthermore, cells which do not complete cell replication and cell routing at the routing crossbar are sent to the concentrator. That is, the ratio of cells lost by concentration at the concentrator increases and the cell loss probability is degraded. Second, we propose a crossbar ATM switch where the concentrator is removed and all the output lines of the header translator are connected to a shared buffer, as the proposed model 2. We use computer simulations to compare the performance of proposed model 2 with that of proposed model 1 for mixed traffic with unicast anal multicast cells with respect to cell loss probability and mean delay. It is shown that proposed model 2 can improve cell loss probability performance dramatically for low and medium loads.