高速IP路由器中输入排队调度算法综述

A Survey on Input-Queued Scheduling Algorithms in High-Speed IP Routers

高速IP路由器一般采用基于定长信元的交换结构,其可扩展性和性能分别受排队策略和调度算法的影响.基于输入排队策略的路由器具有良好的可扩展性,但需要一个有效的调度算法的支持,才能保证吞吐率和延迟等性能.主要讨论输入排队调度算法,将现有的调度算法分为4类:最大(无权重)匹配、最大权重匹配、稳定婚姻匹配和确定型调度.对每一类算法,从技术特点和性能指标两个方面进行比较和分析.最后给出了输入排队调度算法的发展趋势.

Most high-speed IP routers exploit cell-based switching fabrics, whose scalability and performance are mainly affected by queuing scheme and scheduling algorithm. Input-queued router is referred to as an ideal structure in terms of scalability. However, it needs an efficient scheduling algorithm to guarantee throughput and delay. Several input-queued scheduling algorithms are surveyed in this paper. The scheduling algorithms are classified into four classes: maximum size matching, maximum weight matching, stable marriage matching, and deterministic scheduling algorithm. The similarities and the difference of different algorithms in mechanisms of each class are described, and their performances are compared. Finally, the future directions and possible open problems are discussed.