On practical solutions of AQM queues with large buffers

In a router equipped with the active queue management (AQM), the arriving packets may be rejected even if the buffer is not full. This is supposed to reduce the queue size, while maintaining a high link utilization. The simplest approach to AQM is rejecting arriving packets with the probability that is a function of the queue length. The recently developed mathematical models of such systems present numerical difficulties that are not trivial to overcome, especially in systems of large sizes. In this paper we first overview the analytical solutions of these models, which contain both Markovian (Poisson) and non-Markovian (general renewal) traffic models. Then we discuss the computational techniques that enable solving and designing of such AQM queues with buffers for thousands of packets. Finally, we demonstrate computational examples with such buffers.