Performance Analysis of Proactive and Reactive Transport Protocols using a Proactive Congestion Avoidance Model

This paper attempts to establish the fact that Proactive transport protocols are better than conventional Reactive transport protocols in terms of overall utilization of resources. This has been proved analytically in this paper using a mathematical model developed for proactive congestion avoidance. The paper also provides a mathematical framework for Proactive Transport Protocol and predicts the congestion window evolution and throughput achieved by single and multiple proactive TCP flows. The congestion window evolution and throughput of a Proactive TCP connection are modeled as functions of the bandwidth, delay, packet size, number of concurrent TCP flows and the penalty factor used by the proactive protocols. Results obtained from the model are verified with ns2 simulation. The optimal value of the penalty factor is derived mathematically from the designed model. It has also been shown how the derived optimal values enhances the performance of the protocol and almost a near maximum utilization of resources is achieved by extensive simulation in ns2 considering both single and multiple TCP flows.