A Sliding-Window Based Efficient Forwarding Mechanism in Shared Memory Switch Fabric

Shared memory switch fabric is the dominant technology in single board switching and the front switching in high-speed switch systems, over which multicast should be well supported. The currently two important forwarding mechanisms are dedicated multicast queue (DMQ) and address copy queue (ACQ). This paper studies the efficiency of ACQ in terms of memory utility, and proposes a sliding-window based multicast-unicast promiscuous address copy queue (SWPACQ) model. Theoretical analysis and numerical emulation show that SWPACQ is a significant enhancement of ACQ, with its performance at least equivalent with ACQ. In given multicast proportion and fan out, the proposed scheme can demonstrate a considerable improvement.