Available Bandwidth Based Congestion Avoidance Scheme for TCP: Modeling and Simulation

Available bandwidth being the capacity of the tightest link along a data path established by virtual circuit service paradigm, is being proposed as an efficient congestion avoidance scheme for TCP to be deployed on a grid system. To achieve our goal, we modified the congestion avoidance segment of the reno version of TCP - multiplicative decrease; by replacing it with a scheme based on available bandwidth. The proposed scheme was modeled using finite automata theory and simulated in Matlab7.0 across a 10-hop of 1Gbps per link data path. To estimate available bandwidth, the size of the probing packet was set to 100 packets using nonintrusive probing method. We observed that our estimation algorithm converged, at most, at the third iteration and at steady-state, TCP current window size increased by 3000-4000% at 95% confidence interval.