Study of Dynamic Timeout Strategy based on flow rate metrics in high-speed networks

The measurements based on flow characteristics are playing more and more important roles in the analysis of Network Behavior. As one of main methods for flow recognition, the timeout strategies have a significant impact on the correctness and performance of flow measurements. This paper discusses the state-of-art of flow timeout strategies, and explains where they are applicable and their shortcomings. To deal with short flows that take a large part of the total flows in the networks, the paper proposes the Dynamic Timeout Strategy (DToS) by analyzing flows distribution and flow rate metrics in details. The studies show that this method can improve the performances of network measurement and the efficiency of the resource usage by using different timeout strategies to deal with flows that have different rate features based on integrated usage analyses of target networks. It can also apperceive network abnormal behavior efficiently, and then take emergent measures to ensure the safety of measurement system. Some experiments have been carried out to show the rationality of DToS strategy. The applicable area of this strategy is also analyzed at the end of this paper.