Scheduling multicast traffic in internally buffered crossbar switches

Scheduling multicast traffic has been an active research topic due to the tremendous growth of multicast traffic (audio, video, teleconferencing, etc.) on the Internet. Considerable research work has been done on input queued (IQ) switches to handle the multicast traffic. Unfortunately, all the proposed solutions were of no practical value because they either lack performance or were simply not practical. Internally buffered crossbar (IBC) switches, on the other hand, have been considered as a robust alternative to buffer-less crossbar switches to improve the switching performance. However, no work has ever been done on multicasting in IBC switches. In this paper, we fill this gap and study, for the first time, the multicasting problem in IBC switches. In particular, we propose a simple scheduling scheme named multicast cross-points round robin (MXRR) for the IBC switch architecture. Our scheme was shown to handle multicast traffic more efficiently and far better than all previous schemes. Yet, MXRR is both practical and achieves high performance.