Packet scheduling algorithm for mixed unicast and multicast traffic in CICQ switches based on Work-Conserving

A new crossbar buffer balanced scheduling algorithm called multicast and unicast crossbuffer balance (MUCB) is proposed for combined input and crossbar queued (CICQ) architecture switches, which accommodates mixed unicast and multicast traffic. Different from the popular algorithms mainly based on traffic state such as queue length and/or waiting time, the proposed algorithm aims to make the switch operate in Work-Conserving state to the largest extent by balancing the occupancy of crosspoint buffers. In addition, to achieve high throughput and the scheduling fairness at the same time, the proposed algorithm considers enough the difference between unicast traffic and multicast traffic as well as the mutual influence relations of input scheduling and output scheduling in a CICQ switch. Simulation results demonstrate that under different proportions of multicast traffic, compared with the existing popular algorithms for a CICQ switch, MUCB algorithm can significantly improve the total performance in terms of throughput and average packet delay for the mixed unicast and multicast traffic.