用于多级交换网络的一种高效自寻路技术

An Efficient Self-routed Scheme for Multi-stage Switching Network

自寻路交换是多级交换网络中的一种常用技术,但它容易因冲突而形成网络内部阻塞。为减少连续冲突,进一步提升网络性能,基于三级Clos网络,提出了一种新的高效自寻路机制。通过在交换网络前端采取"信元间插"策略,将分组的连续信元在时间轴上打散,保证业务被均匀地发送至网络中,从而大大减轻了网络内部阻塞;同时,通过在第一级交换单元中设置"逻辑指示器",为不同的业务流合理地选取第二级交换单元,一定程度上保证了第二级的负载均衡。理论分析和仿真实验表明,与CRRD(Current Round-Robin Dispatching)等其他交换调度方式相比,新自寻路机制下的信元平均网络时延明显减小。

Self-routed switching is a common technique in the multi-stage switching network.However,it is easy to cause internal network blocking because of the conflict.In order to reduce the continuous conflicts and enhance the network performance,a new efficient self-routed scheme based on three-stage Clos network is proposed.This scheme can distribute the continuous cells of the packet discretely on ＂time axle＂ by the way of ＂cell interleaving＂,ensuring that cells belonging to a given stream are transmitted into the fabric at well-spaced intervals of time,thus greatly reducing the continuous obstruction within the network.Besides,a group of ＂logic indicators＂ is set in every switching unit in the first stage for different streams to choose proper second stage units,which helps to keep load balance of the second stage modules.Analysis and simulations show that the average network delay in the new scheme is significantly decreased in comparison with some other switching methods such as CRRD（Concurrent Round-Robin Dispatching）.