Improvements of the SABUL Congestion Control Algorithm

Several new protocols such as RBUDP, UserLevel UDP, Tsunami, and SABUL, have been proposed as alternatives to TCP for high speed data transfer. The purpose of this paper is to analyze the effects of SABUL congestion control algorithm and its parameters on SABUL bandwidth utilization by using extensive simulations. The simulation results show that SABUL congestion control parameters have a direct impact on SABUL bandwidth utilization and SABUL cannot compete with uncontrolled flows such as UDP. We propose a modification of SABUL congestion control algorithm to improve the overall performance of SABUL and use ns2 simulations to verify our algorithms. Our results show that with two modifications, SABUL can achieve a better bandwidth utilization even when protocol parameters have been chosen improperly; moreover, the modified SABUL algorithm can achieve a better bandwidth utilization when competing with uncontrolled traffic.