Design of a scalable hybrid multicast packet switch with optical fabric

A multi-rack switching system usually combines electronic and optical technology, using electronic buffers, optical fabric and interconnections. In this paper, we consider the design a scalable hybrid packet switch which efficiently transmits multicast traffic. The switch is equipped with a passive optical fabric, and each of its racks operates individually and independently. Multiple multicast queues are used in input ports to partially resolve HOL problem. A simple Priority Fanout Filling (PFF) algorithm is proposed to improve the bandwidth usage with the help of a local crossbar. PFF is shown to be fair, work-conserving and guarantees sequential delivery for multicast traffic. All these features make the switch scalable and achieve high-performance. Furthermore, from a practical point of view, the switch is easily to be implemented.