Active Queue Management for differentiated service network

The presented Active Queue Management (AQM) algorithms are not suitable to the DiffServ task, which may lead to serious network congestion problem. To solve the problem, this paper develops a DiffServ AQM algorithm based on nonlinear difference equations. The control algorithm takes into consideration the committed information rate and maximum allowed burst size of the marker, in addition to the number of DiffServ flows in an aggregate, round trip time, and the probability of a packet dropping at the DiffServ network. Two theorems have proposed to prevent the congestion of DiffServ networks. Observations from the system simulations are presented, and simulations were performed to validate the accuracy of the control algorithm. The simulations for two classes of DiffServ flows verify the proposed DiffServ AQM algorithms to be valid, the performance of DiffServ is largely flow-based rather than desired-aggregate-based, and the congestion of DiffServ network can be prevented by the proposed approach.