提出了区分服务中一种基于预测的主动队列管理算法PIO。在PIO算法中,首先对IN包和所有包下一时段的平均到达速率进行预测。当包到达队列时,根据当前IN包队列长度、总的队列长度、预测的下一时段所有包的平均到达速率和IN包平均到达速率决定对包是否丢弃。通过仿真实验,分析了在不同预约比例、不同端到端TCP连接数的条件下PIO算法队列稳定性、丢包率和吞吐量等性能指标。仿真结果表明,PIO算法在统计性保证带宽的同时,与RIO算法相比,无论是在低预约还是过预约网络状态下都有效提高了队列的稳定性,并降低了丢包率。
A new active queue management algorithm-PIO based on the prediction of the arrival rate in DiffServ networks is proposed. In PIO, the average arrival rate for IN packets and all packets in the next interval are predicted firstly. The PIO algorithm decides whether or not to drop the arriving packet according to the queue length for IN packets, the total queue length for all packets, the predicted arrival rato for IN packets and all packets in the next interval. Through the simulation, the PIO performances with respect to the stabilization of the queue, packet loss ratio and attainable throughput under the different subscription ratio and the different number of connections are analyzed. The simulation results indicate that PIO compared with RIO improves the stabilization of queue and reduces packet loss ratio efficiently whether the network is under-subscribed or oversubscribed, while providing statistical assurance for the bandwidth.