Active Queue Management (AQM) can potentially reduce packet loss rate in the Internet. This is used by routers for control congestion, where packets are dropped before queues become full. A number of active queue management algorithms for TCP/IP networks such as random early detection (RED), Fair RED (FRED), BLUE, Stochastic Fair Blue (SFB), and Corestateless Fair Queuing (CSFQ) have been proposed in the past few years. This article presents a comparative study of these algorithms using ns-2 simulations. The performance metrics used in the study are queue size, packet drop marking probability, packet loss rate and bandwidth utilization. The study shows that BLUE is better than RED to avoid global synchronization for maintaining single marking probability. And also, the results shows that, among the five algorithms, SFB and CSFQ are more effective at stabilizing the queue size and controlling the packet loss rate among non-responsive flows while maintaining high link utilization. The performance of SFB and CSFQ are obviously better than that of RED,FREDand BLUE.

Key words : Congestion Control, Fair Queue, Networks, Queue Management