Network management and control is a complex problem that requires robust, possibly intelligent, control methodologies to obtain satisfactory performance. Active Queue Management (AQM) mechanisms have been introduced to assist the TCP congestion control. We discuss the modeling and control approach followed by a number of representative AQM schemes, and address possible limitations to meet the d...

This paper studies congestion control in local wireless networks supporting transmission control protocol (TCP) under random early detection (RED). In general, congestion delays may cause instability of the routers running active queue management (AQM) protocols such as RED. Moreover, its management efficiency could be reduced by serious queue oscillation. To improve these two drawbacks, we pro...

Over the last decade numerous Active Queue Management (AQM) schemes have been proposed in the literature. Many of these studies have been directed towards improving congestion control in best-effort networks. However, there has been a notable lack of standardised performance evaluation of AQM schemes. A rigorous study of the influence of parameterisation on specific schemes and the establishmen...

Two key mechanisms of the Internet are congestion control in Transmission Control Protocol (TCP) and Active Queue Management (AQM) routers. The former divides bandwidth between flows prevents from collapse. Simultaneously, latter informs hosts forthcoming by preventive dropping packets network nodes. Although these two may severely interact with each other, they often being researched independe...

In recent years, AQM (Active Queue Management) mechanisms, which support the end-to-end congestion control mechanism of TCP by performing congestion control at a router, have been actively studied by many researchers. AQM mechanisms usually have several control parameters, and their effectiveness depends on a setting of those control parameters. Therefore, issues on parameter tuning of several ...

In this paper, we propose an efficient control scheme for active queue management (AQM) supporting TCP flows. The proposed controller consists of two parts: a rate controller and a queue size controller. The rate controller is a proportional-integral (PI) controller, which improves the response to dynamic traffic variation and keeps the packet arrival rate around the link capacity. The queue si...

Over the last decade numerous Active Queue Management (AQM) schemes have been proposed in the literature. Many of these studies have been directed towards improving congestion control in best-effort networks. However, there has been a notable lack of standardised performance evaluation of AQM schemes. A rigorous study of the influence of parameterisation on specific schemes and the establishmen...

In this work, we investigate the congestion control problem for layered video multicast in IP networks of active queue management (AQM) using a simple random early detection (RED) queue model. AQM support from networks improves the visual quality of video streaming but makes network adaptation more difficult for existing layered video multicast proticols that use the event-driven timer-based ap...

A NEW PI AND PID CONTROL DESIGN METHOD AND ITS APPLICATION TO ACTIVE QUEUE MANAGEMENT OF TCP FLOWS Deniz Üstebay M.S. in Electrical and Electronics Engineering Supervisor: Prof. Dr. Hitay Özbay June 2007 PID controllers are continuing to be used in many control applications due to their simple structures. Design of such controllers for unstable systems with time delays is an active research are...

We evaluate the performance of modern delay-based active queue management (AQM) algorithms in downstream DOCSIS 3.0 cable environments. Our simulation-based study involves scenarios that include tiered service levels and application workloads that include FTP, HTTP-based adaptive streaming (HAS), VoIP, and web traffic. Our results show that AQM maintains target queuing delays and consequently p...