Skip to Main Content
Random Early Detection (RED) is recommended as the congestion avoidance mechanism in packet switched networks in RFC2309 and has become the focus of much research into congestion control. Furthermore, RED and WRED are the AQM schemes most widely deployed in commercial Internet routers, such as Cisco and Juniper routers. This paper describes an analytical approach that models RED and WRED schemes using a discrete-time queuing model with superposition of N MMBP-2 sources as arrival processes. Each MMBP-2 represents an aggregated Internet traffic flow from different traffic classes or with different precedence. Performance analysis for RED and WRED are then carried out using different dropping profiles through Matlab numerical analysis based on the proposed queuing model. Performance measures, such as throughput, mean queuing delay and loss probability, obtained from analytical analysis are studied; the trade-off between packet loss and queuing delay can then be evaluated easily for different traffic classes. In this way, the proposed analytical model facilitates fine tuning of RED and WRED parameters for the purpose of QoS provisioning and capacity planning on Internet routers.