SCI/RT总线的扩展子优先级流量均衡

Simulation of SCI/RT extending sub-priority loading balance protocol

建立了基于OPNET软件的SCI/RT(Scalable Coherent Interface for RealTime)TRAIN协议仿真模型,对流量均衡问题进行仿真分析.结果显示,当环路负载增加时,每个节点流量的增量是不同的.在环路处于重负载时,远离管理者的节点得到的流量近似于零,而靠近管理者的节点基本上占用了所有的环路流量.SCI/RT TRAIN协议提出管理者迁移流量均衡方式解决这个问题.通过对8节点环路进行仿真,得出管理者迁移方法的均衡效果依赖于管理者在环路的配置方式的结论,当每个节点均具有管理者功能时,环路均衡效果达到最好.提出了扩展子优先级的流量均衡新方法.8节点环路的仿真结果显示,该方法具有更好的流量均衡能力和更高的节点流量.同时,通过对扩展子优先级均衡方法在6节点,10节点和12节点环路的仿真,证明了该方法在不同规模的环路中均可使用.

To analyze the loading balance problem, the scalable coherent interface for real time （SCI/ RT） TRAIN protocol was simulated by using OPNET. The results show that the incensement of the nodes throughput is quite different from each other, along with the ringlet load increasing. In case of the heavy ringlet load, the down stream nodes far from ticketmaster gained almost zero load, while the nodes near ticketmaster gained almost all the ringlet load. The SCI/RT TRAIN protocol gave the tieketmaster migration method to solve it. According to the simulations of a ringlet of 8 nodes, the ticketmaster migration method can distribute load between ringlet nodes but the performance of its function is very dependent on its configuration. When every node has the ticketmaster module, the method gets its best function. In this work, a new comparative method named extending sub-priority was proposed. It was proven that the extending sub-priority method gets better loading balance and higher node throughput than the previous ticketmaster migration method. On the other hand, based on the simulations of 6 nodes, 10 nodes and 12 nodes ringlets, the proposed extending subpriority method was proven to be functional in ringlets with different scales.