A Study On Measuring The Network Bandwidth Technology

Network bandwidth is a crucial resource in the Internet. Understanding the network bandwidth behavior is an important task for network measurement. Measuring the network bandwidth will be beneficial for many aspects such as network management, network planning and design, and improving the performance of the network applications. Therefore, measuring the IP network bandwidth has become a hotspot research issue in Internet.This paper summaries the current techniques for measureing the network bandwidth and analyzes their principle firstly, performance and limitation in detail. Based on the others'initiated works, some new methods used in the aspect of bottleneck bandwidth measurement and available bandwidth measurement, are put forward. Also some tools are implemented.A new measurement model called double packet pair is put forward for measuring the bottleneck bandwidth. The double packet model uses the differentiate relation between the two packet pairs in a packet pair to eliminate the disturbance of the data link layer. So the double packet pair model has the higher accuracy on measurement. Because the measurement samples in the double packet pair model are preprocessed, the robustness is also stronger than the packet pair model.A rate-limited packet train model is put forward for measuring the available bandwidth. In this model, the packet train, whose initial rate is equal to the path capacity, is used to measure the instant available bandwidth. In order to monitor the available bandwidth during a long period, a new algorithm called self-adaptive measurement interval time selecting algorithm is put forward to select the measurement time point.