Author : Tanvi Sharma

Network management and control is a complex problem, which is becoming even more challenging with the increased demand to use the internet for time/delay-sensitive applications with differing QoS requirements. The existing TCP congestion avoidance and control mechanisms are insufficient to provide good service in all conditions. The TCP has successfully governed the Internet congestion control for two decades. It is by now, however, recognized that TCP has started to reach its limits and that new congestion control protocols are needed in the near future. This has spurred an intensive research effort searching for new congestion control designs that meet the demands of a future Internet. Despite massive awareness and research, the full buffer problem has not gone away, but on the contrary has become worse. Therefore, there has been an increased interest in exploring AQM in Internet routers so as to reduce the queue latency. This research describes a recently developed AQM, Controlled Delay (CoDel) algorithm, designed to work in modern network settings and can be deployed as a major part of the solution to bufferbloat. Effectiveness of CoDel is tested by carrying out simulations in ns-2 and comparing its performance with two other promising network queue management algorithms, RED and DropTail. The CoDel AQM displays extremely good performance in most bufferbloat traffic scenarios.

Keywords: Active Queue Management, Bufferbloat, CoDel, Congestion control, Random Early Detection, DropTail, Queues.

Article published in International Journal of Current  Engineering  and Technology, Vol.4,No.3 (June- 2014)