Research and Simulation of Queue Management Algorithms between DropTail and RED

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.