With the continuous increasing demand of internet applications. Network`s are expressing a serious congestion problem. In very large networks with heavy load traffic, Internet routers play an important role during congestion. All the internet routers have some buffers at input and output port which holds the packets in the time of congestion. Many queue management algorithms have been proposed but they mainly focus on fixed queue limit. Recognizing the fact that drop tail algorithm has fix maximum queue limit ,we direct our attention to variable Length queue limit for Combined Input and Output queued (CIOQ) switches. We propose a simple modification to the drop tail algorithm in which a generic queue management controls methodology in TCP/IP networks, that case we dynamic change queue length in our wired network. The performance of the proposed controlled system is evaluated via NS- 2 simulator.
