基于缓解HoL堵塞的单组播混合调度算法

针对联合输入交叉队列（CICQ）结构的单组播混合调度研究不多,且没有针对性研究头分组（HoL）堵塞问题,提出了以缓解HoL堵塞为目标的一种新的单组播混合调度算法,即单组播低HoL堵塞（MULHB）算法,使交换机尽量逼近work-conserving状态。该算法还充分考虑了单组播之间的差异性,利用权重裁决单组播之间的竞争,避免"饿死"现象发生。同时,还给出了一种新的组播分组入队算法,即动态组播分组入队（DMQ）策略,该策略在不乱序的前提下,允许新到达分组选择合适的队列入队。仿真结果表明,在不同业务下,DMQ-MULHB算法的通过率及平均时延均优于现有主流的单组播混合调度算法,尤其在非均匀业务下,该算法性能接近输出排队（OQ）调度。 

Packet scheduling algorithm for integrated unicast and multicast traffic based on reducing HoL blocking

In view of the problem that few researches have been done on the mixed scheduling of unicast and multicast traffic for the combined input and crossbar queued (CICQ) architecture, and there is no research on the head of line (HoL) blocking problem, a new scheduling algorithm for mixed multicast and unicast, i.e. unicast with low HoL blocking (MULHB) algorithm, is proposed, which aims to reduce HoL blocking so that the switch can operate in work-conserving state as much as possible. In addition, to avoid the phenomenon of "starvation", the proposed algorithm considers the difference between unicast traffic and multicast traffic and uses weights to complete the arbitration between unicast and multicast. At the same time, this paper also proposes a dynamic multicast cell assignment algorithm named dynamic muticast queuing (DMQ), which allows the arrival multicast cell to select the appropriate queue without disorder. Simulation results show that the performance in terms of through rate and average packet delay obtained by DMQ-MULHB is much better than that of the existing popular algorithms under the different traffic patterns, and especially under the non-uniform traffic pattern, the performance is close to the output queuing (OQ) scheduling.