光弹性分组环节点光分组的组装及时延分析

Assembly and Delay Analysis of Optical Resilient Packet Ring on Packets Encapsulation

分析了光弹性分组环(ORPR)网络中流量成型时光分组组装算法,提出一种适合ORPR网络的基于控制发送时间的光分组组装算法,并给出了该算法的算法结构。该算法在混合门限组装算法的基础上,通过增加一个控制分组发送间隔的参数,使得光分组单位时间内流量的突发性被平滑,并可以保证ORPR网络的服务质量(QoS)性能,适合于使用容量有限光缓存的ORPR网络。对ORPR节点光分组平均组装时延进行了详细的分析,新算法通过对分组发送间隔的调整,使在不同负载条件下,组装时延的概率分布基本相同。在ORPR中,平均组装时延的稳定对ORPR网络的QoS性能和公平性调度有重要意义,而发送时机的合理选择,可以保证ORPR网络的QoS性能以及公平性。仿真结果表明,新算法使得ORPR网络中的光分组平均组装时延相对稳定,在大多数情况下,可以保证ORPR网络的调度要求。

Optical packets assembly algorithm is analyzed when traffic shapes in an optical resilient packet ring （ORPR） network and a new algorithm is proposed for ORPR network by controlling the time in transmission. The algorithm is based on a hybrid threshold assembly algorithm. It adds a parameter to control the interval between optical packets so that the traffic in each time unit is smoothed. It also ensures the quality of service （QoS） performances of the network and fits for the ORPR network with limited optical buffer. The average assembly timedelay of optical packets is analyzed in detail. By adjusting the interval of packet transmission in the new algorithm, we obtain about the same distribution of assembly time-delay under different traffic loads. The stable packets average assembly time-delay is very important to QoS and fairness of ORPR. Choosing the good timing for packet transmission is one of the keys to ensure the QoS and fairness of the ORPR. Simulation results demonstrate that the new algorithm gives a relatively stable packets average assembly time-delay and dispatching is satisfied in most situations in the ORPR network.