Research On Trusted Network Congestion Control Based On AQM

With the rapid development of Internet, the problem of network congestion is more and more serious. It is causes widespread concern. Therefore, many scholars join into study the network congestion control. In recent years, active queue management technique of improving the Quality of Service has become the hot spot of the scholars'research.Departure from the concept of the congestion control, and analysis the congestion control mechanism: TCP-based congestion control mechanism and link-based congestion control mechanism. Many AQM algorithm based on classical linear control theory analysis and design, for example: RED and PI etc, having improved the link utilization and lower packet loss ratio. However, the network system is complex and changes. AQM algorithm based on linear control theory is not adapted to the characteristics of the nonlinear dynamic of the network system.In this paper, design an AQM algorithm based on the nonlinear control theory of variable structure control (VSC). It is good to deal with the characteristics of the nonlinear dynamic of the network system. Through in-depth study and analysis of VSC algorithm, in the case of load changes and different round-trip time of the nonlinear TCP/AQM has better stability and robustness. Finally, NS2 simulations are provided to validate the design and compare its performance to the other AQM algorithm from the different angles. The results show that VSC algorithm outperforms the other AQM algorithm in the terms of queue length, throughput, link utilization and packet loss ratio. Verify a strong robustness and stability of VSC algorithm.