Integration of look-ahead multicast and unicast scheduling for input-queued cell switches

This paper presents an integration of multicast and unicast traffic scheduling algorithms for input-queued cell switches. The multi-level round-robin multicast scheduling (ML-RRMS) algorithm with the look-ahead (LA) mechanism provides a highly scalable architecture and is able to reduce the head-ofline (HOL) blocking problem that the weight-based algorithm (WBA) suffers from. Leveraging the FILter & Merge (FILM) scheme, multicast and unicast traffic are independently scheduled based on their requests. Decisions are integrated following a specific policy. Remainder is looped back to the filtering module that filters out the conflicting requests to ensure fairness. Simulation results show that comparing with the scheme using WBA for the multicast scheduling, the scheme proposed in this paper reduces the HOL blocking problem for multicast traffic and provides a significant improvement in terms of latency.