An Improved IGI Available Bandwidth Probing Technique

The conventional IGI (Initial gap increasing) method can significantly impact the cross traffic. In this paper, we propose an improved IGI method for the problem. With the reasons why the IGI method can significantly impact cross traffic, the method of finding turning point is modified. Firstly, the larger initial gap is chosen, and the gap is decreased step by step to reach the turning point. The turning point is judged based on the principle that the output gap is larger than input gap. Using ns simulations, the performance about the measurement accuracy and the impact of probe traffic on the cross traffic is respectively compared between the improved and traditional IGI method, which proved that the improved method can maintain the advantages and reduce its impact on the cross traffic.