Review of Queue Management in Packet Switched Networks

Abstract

This paper gives a state of the art review of congestion control and active queue management (AQM) in packet networks. We also illustrate the latest phase of congestion control, adaptive active queue management. It supports end-to-end control for packet data traffic between intermediate nodes of the network. AQM is a trade-off between link utilisation and the delay and loss of transmitted packets. It is a mechanism to avoid incipient or persistent congestion in bottleneck router, the increase utilization of bandwidth, minimize jitter, and decrease datagram delay and loss. The transmission control protocol (TCP) solves end-to-end flow control with a sliding window scheme, but it does not have a mechanism for congestion control. It only performs end-to-end congestion avoidance and flow control. AQM algorithms are enhancements for the commonly used Drop Tail (DT) algorithm. The advantage of AQM based algorithms is their ability to notify a host about incipient congestion before the actual congestion by dropping or marking datagrams.