Multicast ATM switches using buffered MIN structure: a performance study

A (large) multicast ATM switch with an external structure of output queueing and an internal structure of buffered MINs (multistage interconnection networks) is considered, where the buffered MINs (also called a switching network) are composed of switching elements with shared buffer output queueing. A cell replication while routing scheme is used in the switch to implement the multicast function. In this paper, we study the performance of the switch with multicast traffic, mainly via computer simulations. The multicast traffic can be random and bursty. From our study we found that for multicast traffic with a truncated geometric distribution of cell fanouts it has only a slightly worse impact on the performance of the switching elements in isolation or in the last stage of the switching network. The multicast traffic has no worse effect on the switch output buffer behaviour and cell delay in the switching network. Moreover, traffic splitting can substantially improve the switching network performance for highly bursty traffic. Some analytical approximations are given which could be useful in the dimensioning of switching networks.