可行的基于CIOQ的并行分组交换结构

摘要

For the plane extension problem of conventional parallel packet switch, a practical distributed parallel packet switch (PDPPS) was proposed. For a PDPPS with N ports and K central planes, each multiplexor only needed to maintain NK high-speed buffers to guarantee the orderly transmission of each flow. Theoretic analysis and simulation results show that the performance of PDPPS is better than that of VIQ PPS(virtual input queuing parallel packet switch) whose central plane is OQ(output queuing), and slightly worse than that of centralized PPS and IOQ PPS(in-order queuing parallel packet switch). But compared with centralized PPS, the PDPPS makes use of CIOQ(combined input and output queuing) as central plane which is more common and easier to implement, compared with IOQ PPS, the PDPPS schedules in a distributed way, which eliminates communication overhead. And the PDPPS dramatically reduces the amount of required high-speed buffer.%针对传统并行分组交换结构存在的平面可扩展性问题,提出一种可行的分布式并行分组交换PDPPS(practical distributed parallel packet switch).在端口数为N和中间层平面数为K的情况下,PDPPS的复用器中只需要维护大小为NK的高速缓存,就能保证每条流按序输出.理论分析和仿真结果表明,PDPPS的性能优于使用OQ(output queuing)结构作为中间层平面的分布式并行分组交换结构VIQ PPS(virtual input queuing parallel packetswitch),略微低于集中式PPS和IOQ PPS(in-order queuing parallel packet switch).但相对于集中式PPS,PDPPS使用了更为通用且易于实现的CIOQ(combinedinput andoutputqueuing)作为中间层平面;相对于IOQPPS,PDPPS使用了分布式调度算法,从而消除了系统的通信开销,并且PDPPS极大地降低了所需的高速缓存数量.