支持公平服务的CICQ分层混合调度策略

为到达业务提供性能保障是衡量一个交换系统性能的重要参考.针对现有联合输入交叉点排队交换结构(CICQ)调度策略缺乏基于流的服务质量保障,探讨了在CICQ交换结构实施基于"流"调度的可能性,提出了一种能够为到达业务流的提供公平服务的分层混合调度策略(HSFS).HSFS采用分层的混合调度机制,每个输入、输出端口可独立地进行变长分组交换,其复杂度为O(1),具有良好可扩展特性.理论分析结果表明,HSFS无需加速便能为到达业务提供时延上限、速率和公平性保障.最后,基于SPES对HSFS的性能进行了评估.

Achieving fair service with a hybrid scheduling scheme for CICQ switches

Providing performance guarantees for arriving traffic flows has become an important measure for today’s routing and switching systems.However,none of current scheduling algorithms built on CICQ(combined input and cross-point buffered) switches can provide flow level performance guarantees.Aiming at meeting this requirement,the feasibility of implementing flow level scheduling is discussed thoroughly.Then,based on the discussion,it comes up with a hybrid and stratified fair scheduling(HSFS) scheme,which is hierarchical and hybrid,for CICQ switches.With HSFS,each input port and output port can schedule variable length packets independently with a complexity of O(1).Theoretical analysis show that HSFS can provide delay bound,service rate and fair performance guarantees without speedup.Finally,we implement HSFS in SPES(switch performance evaluation system) to verify the analytical results.