Research And Implementation For Congestion Control Algorithm Based On Active Network

Network congestion continues to persist and grow in spite of continued research efforts in industry and academia to eliminate it. Closed-loop congestion control mechanisms have become the norm in the Internet today. In these mechanisms, the network provides negative feedback to the transmitting sources when it is congested or when congestion is building up. The mechanisms then rely on the transmitting sources to exercise control by cutting back their effective rate of transmission. However, an increasing number of applications such as voice, audio and broadcast services require a constant bit rate of transmission, while some others, e.g. streaming and multimedia applications, Internet telephony and fast data exchange services, tend to "grab" as much network bandwidth as available. These applications by their very nature tend to ignore or underplay congestion-related feedback from the network.The Random Early Detection (RED) mechanism for congestion avoidance helps keep the average queue size low, allows occasional packet bursts, and prevents global synchronization of source windows due to its randomness in marking or dropping packets at a congested node. However, it has been proven through simulations that an unresponsive bandwidth-greedy connection gets a larger than fair share of the bandwidth at a bottleneck link when competing with responsive connections at a RED gateway.Active networks provide an innovative networking platform that is flexible and extensible at runtime and supports the rapid evolution and deployment of networking technologies to suit current needs. In this paper we present the design, implementation and evaluation of the high bandwidth delay congestion control mechanism that uses active network capabilities that to address the shortcomings of RED and limit the degradation in network performance caused by high bandwidth application flows. High bandwidth delay congestion control mechanism limits the impact of high bandwidth connections at a congested node. The new mechanism is proved to be efficient and valuable through the experiments.