有优先级的输出排队快速分组交换机性能研究

输出排队结构是快速分组交换中交换性能最佳的交换结构。本文研究输出排队结构交换任意种优先级业务的排队性能。分别在独立和相关到达两种情况下导出了任意优先级业务的平均排队长度等特征参数,发现当N×N规模互连网络的端口数N足够大时,两种业务到达模型的排队性能趋于一致。文中提出了一种数值迭代法来求取用二维Markov过程表示的高、低优先级分组队列长度的稳态解。计算机模拟结果证实了文中的分析。

A Study on Performance of Output Queueing Fast Packet Switch with Priority Classes

Output queueing is the optimal switch of fast packet switching in performance. In this paper, the queueing performance of output queueing with arbitrary priority classes is studied. We derive the statistical characteristics, such as average queue length of any priority packet in independent and dependent packet arrival cases. It is found that for an N xN output queueing switch, the queueing performance of both cases tends to be the same if N is large enough. A numerical iteration is presented to get the stationary queue length distribution of high and low priority packets with queueing equation in two dimensional Markov process. The analyses are proved correct by computer simulation.