FTMS: An Efficient Multicast Scheduling Algorithm for Feedback-Based Two-Stage Switch
Two major challenges in designing high-speed multicast switches are the expensive multicast switch fabric and the highly complicated central scheduler. While the recent load-balanced switch architecture uses simple unicast switch fabric and does not require a central scheduler, it is only good at handling unicast traffic. In this paper, the authors extend an existing load-balanced switch called feedback-based two-stage switch to support multicast traffic. In particular, an eFficienT Multicast Scheduling algorithm (FTMS) is designed. With FTMS, Head-OffLine (HOL) packet blocking at each input port is eliminated by adopting "Pointer" queues. To cut down queuing delay, packet replication is carried out at middle-stage ports.