Abstract This paper focuses on the asymptotic stability of proportional-integral AQM controllers supporting TCP flows. Necessary and sufficient conditions for the asymptotic stability of the closed-loop linearization are provided. As a result, the complete set of proportional-integral controllers that locally stabilizes the equilibrium point is obtained. The robustness of the controllers to unc...

In this paper we propose a duality model of congestion control and apply it to TCP and active queue management schemes. Congestion control is the interaction of source rates with certain congestion measures in the network. The basic idea is to regard source rates as primal variables and congestion measures as dual variables, and congestion control as a Lagrangian method that iterates on source ...

Signal transmission control protocol sources with the objective of managing queue utilization and delay is actually a feedback control problem in active queue management (AQM) core routers. This paper extends AQM control design for single network systems to large-scale wired network systems with time delays at each communication channel. A system model consisted of several local networks is fir...

Recent work has shown the benefit of using proportional feedback in TCP/AQM networks. By proportional feedback we mean the marking probability is proportional to the instantaneous queue length. Our earlier work relied on linearization of nonlinear fluidflow models of TCP. In this work we address these nonlinearities directly and establish some stability results when the marking is proportional....

Active queue management (AQM) is an important function in today’s core routers that will be required in the future optical internet core. A recently reported novel architecture for optical packet buffers is extended by implementing necessary AQM functions. The suggested AQM scheme is validated and explore via simulations.

The Random early detection (RED) active queue management (AQM) scheme uses the average queue size to calculate the dropping probability in terms of minimum and maximum thresholds. The effect of heavy load enhances the frequency of crossing the maximum threshold value resulting in frequent dropping of the packets. An adaptive queue management with random dropping (AQMRD) algorithm is proposed wh...

In this paper we present new model-based controllers for active queue management (AQM) supporting TCP ows. Our control design is based on linearization of a previously developed TCP model using uid ow and stochastic di erential equations. An AQM using a simple PI controller is shown to signi cantly outperform RED AQM. However, we show that both AQMs are unable to maintain performance as the num...

We derive the waiting time in a queueing scheme, which an arriving job can be denied service with probability relative to queue size. Such scheme is generalization of tail-drop queue, when buffer (waiting room) full, and found computer networking, call centers other everyday life applications systems. To make model very general, we use arrival process enables shaping arbitrary interarrival dist...

In order to stem the increasing packet loss rates caused by an exponential increase in network traffic, the IETF is considering the deployment of active queue management techniques such as RED [13]. While active queue management can potentially reduce packet loss rates in the Internet, this paper shows that current techniques are ineffective in preventing high loss rates. The inherent problem w...