Modeling and Analysis on MTS-Clos Networks Serving Multi-slot Traffic
Sun Qian Xu Du
Key Laboratory of Optical Fiber Sensing & Communication Ministry of Education, University of Electronic Science & Technology of China, Chengdu 611731, China
摘要 多级Clos网络是一种典型的可扩展交叉互连结构,在数据通信和计算机并行网络中有着广泛应用。基于传统三级Clos网络C(m, n, r)的理论分析表明,当满足m≥2n-1时该网络是严格无阻塞的。该文针对多时隙业务,利用可快速实现时隙交叉的单级交换模块,构建了一种新型的MTS-Clos交换网络结构C(m, n, r)(Multiple Time Slot Clos network)。利用时隙交叉能力,该结构在保留原有网络特性的同时可提供更为理想的交换性能。采用随机分析模型,对该结构的阻塞率进行了理论分析,结果表明当中间级规模m=n+k, k是一个很小的非负整数,网络即达到无阻塞。对该结构的数值仿真有同样的结论。因此,该结构及分析结果对下一代大容量交换设备的设计,具有良好的参考价值。
Abstract:The multistage Clos network or C(m, n, r) is widely deployed in data communications and parallel computing systems because of its scalability. It is well known the network is strictly non-blocking if m≥2n-1. A new architecture of Multiple Time Slot Clos network (MTS-C (m, n, r)) is proposed in this paper, which is based on fast time slot interchangeable unit and serving for multi-slot traffic. The MTS-C (m, n, r) network keeps the original features while providing better switching performance. A new analytical model assuming a random routing strategy is established, and under this model the blocking probability of the C (m, n, r) network is analyzed. The analytical and simulation results show that a C (m, n, r) network with a small number of middle stage switches m, such as m=n+k, where k is small constant, is almost non-blocking for unicast connections.