On the Throughput of Input-Queued Cell-Based Switches with Multicast Traffic

In this paper we discuss the throughput achievable in inputqueued cell-based switches loaded with multicast traffic. The switch architecture is assumed to comprise a synchronous broadcast switching fabric, where fixed-size data units, called cells, can be transferred in one slot from one input to any set of outputs. The switch scheduler must select the time slots for transfers of non-conflicting cells, i.e., cells neither coming from the same input nor directed to the same output. Contrary to the case of unicast traffic, for which input-queued switches were proved to yield the same throughput as output-queued switches, we show by simulation experiments and analytical modeling that throughput limitations exist in input-queued switches loaded with multicast traffic. Keywords-Input queued architectures, IQ switch, multicast traffic,