中文摘要：

随着Internet的快速发展网络拥塞问题随之产生,拥塞控制行之有效的手段是在网络层实现队列管理.队列管理算法可以分为主动队列管理和被动队列管理两种.通过NS2仿真实验,对主动队列管理算法RED、被动队列管理算法DropTail的平均队列长度、吞吐量、丢包率、时延四个主要性能指标进行了比较.将得到的仿真数据进行分析,在队列长度、时延、丢包率方面,RED算法比起DropTail算法有着绝对的优势;在吞吐量方面,两种算法相差不大.因此,得出在队列管理算法中采用RED比采用DropTail更有效,为进一步研究拥塞控制算法提供了依据.

英文摘要：

With the rapid development of network,congestion appears frequently in the Internet.Queue management is an effective mean of congestion control at the network layer.Queue management algorithm can be divided into active queue management and passive queue management.By simulation experiment using NS2,the paper compares the active queue management algorithm RED and the passive queue management algorithm DropTail in the four aspects of the performance：the length of queue,throughput,packet loss ratio and queuing delay.With the analysis of simulation data,it is concluded that in terms of queue length,packet loss,delay,RED algorithm has the absolute advantage over DropTail algorithm; in throughput,two algorithms have little difference.Thus,RED is more effective than the DropTail in the queue management algorithms,and a basis for the further study of congestion control mechanisms is provided.