Research Of Network Congestion Control Algorithm Based On Active Queue Management

Each field of the society has been inseparable from the computer network, the useof the Internet because of the dramatic increase in the number of results in the networkcongestion that is becoming increasingly prominent, which seriously affects the stabilityof the network, so the network communication flow control the problem became moreand more attention. How the stability of quality of network services and network can beeffectively guaranteed, congestion control mechanism play a very important role in thisaspect, it mainly includes active queue management routing and transmission controlprotocol based on end to end the two part based on. AQM control system deployed inrouting end can take the initiative to alleviate and avoid the network congestion, andreduce the queuing delay, packet loss rate and increase the link utilization advantage.But research shows that, AQM algorithm in mutation hybrid flow and dynamic networkscenarios, a link of utilization, low queue performance is not stable enough andparameter configuration defects, therefore received the industry and the wide attentionof the academic circles.In view of this situation, this thesis makes a detailed study of the AQM algorithm.To build a Linux system based on NS2platform, it mainly uses C++and OTCL twokinds of language mix programming model, performance simulation of different scalenetwork algorithm, the result is more close to the actual effect. Then we design aframework of "flow granularity based on" AQM algorithm; moreover, on the basis ofthis, presents a virtual queue algorithm of AQM flow based on perception (VFQalgorithm). VFQ introduced " flow granularity " thought, distinguish and maintenanceby each bottleneck routing traffic flow information; we construct VFQ virtual queuetwo logically independent of the UDP/TCP flow, and the use of congestion controlstrategy is not the same to them; and then with the UDP flow and TCP influenza activityis the feedback current load information, relative the size of the automatic regulation oftwo virtual queue.In this paper, on the platform of NS2VFQ algorithm on a large number ofsimulation, the simulation comparison with several ARED algorithm, PI algorithm, Blue algorithm and other typical AQM algorithm, and the performance of VFQ algorithm areanalyzed, so as to verify the new algorithm is feasibility and effectiveness. Thesimulation results show that: in the face of dynamic load changes, relative to thesealgorithms, VFQ algorithm has the ability of congestion queue convergence speedquickly and efficiently, the congestion of VFQ algorithm can be very good to deal withnetwork.