弹性分组环缓存容量研究

弹性分组环（RPR）是当前城域网发展的重要方向，是为了满足基于分组的城域网的要求而设计的。为了实现基于优先级区分的业务服务质量，弹性分组环采用了基于优先级区分的队列以及转发机制。与传统的队列延时研究方法不同，弹性分组环中的业务接入以及转发延时与当前网络中的拥塞状况密切相关。本文基于弹性分组环协议，建立了弹性分组环转发缓存和接入缓存的排队模型，对弹性分组环中的业务接入时延以及转发队列时延做了定量的分析计算；进而得到弹性分组环中各类优先级转发及接入缓存所需要的容量；利用仿真工具建立了RPR网络的排队传输模型，并进行了仿真验证。仿真结果和理论分析的结果非常接近，从而验证了所建立排队模型的正确性，能够为网络业务配置提供有效的参考；各级缓存容量的结论已经应用在弹性分组环的专用芯片设计之中。

Research on the Buffer Capacity in Resilient Packet Ring

The new requirements of Metropolitan Area Networks(MAN) have resulted in the emergence of novel data transport technology,Resilient Packet Ring(RPR).In order to guarantee the QoS of traffic,Resilient Packet Ring(RPR) has adopted the multiple-channel and multiple-queue to differentiate the traffic with priorities.Being different from the former analysis on delay of queues,the characteristics of the access traffic in RPR has a close relationship with the congestion status of the network.In the paper,the model of transmit-queue and access-queue has been constructed.Then quantitative analysis on the queue delay in access and transmission has been made to get the capacity of the queues with priorities.Simulation on the queue and transmission model has been made to find out that the simulation results are close to those of analysis.Hence,the quantitative analysis has been proved.Through hardware experiments,the conclusions on capacity of queues have been applied in the design of RPR MAC ASIC.