Research And Implementation Of Network Measurement Algorithm Based On Active And Passive Model

With the continuous expansion of network scale and the application of various complex business services, how effectively to obtain network status information is critical to optimize the network setting, enhance network management, improve network service quality and to ensure network security. Network measurement is a direct and effective means to obtain network status information. According to the different measurement method, network measurement generally divided into passive measurement and active measurement. Passive measurements through setting measure station on the nodes or links, record and statistic the network flow information. Active measurement through send probe packets to the target nodes or links to measure network performance parameters. Whether active measurement or passive measurement, it will pay a certain proce. Measure cost generally divided into the equipment deployment, maintenance cost and the impact cost raised by measure behavior. The modern network measurement needs more status information and the measure frequency will be accelerated, which also will make the measure cost rising rapidly. Therefore, the researches of network measure model and algorithm to reduce the cost of measurement have great practical significance.For the network measurement based on active model, the optimization methods of reducing measure cost mainly through reducing the measure station and the probe packets sent. Measure station deployment problem can be mapped to the minimum vertex cover problem. When determining the deployment station, we need to take a reasonable measure assignment to make the measurement cost is relatively low. The real network routing information usually changed dynamically, which requires the measurement can also be dynamical to satisfy the requirments. The passive model-based network measurement, optimization method is to find the lowest measure deployment station set, and to minimize duplication measurement of the network information. The measure station selection problem can be mapped to vertex cover problem. By make use of the traffic flow conservation law, could deduce the problem into weak vertex cover problem, and thus further reduce the measure station deployments. Through the principle of network protocols and network traffic classification, you can further reduce the duplication of network traffic measurements.In this paper, our study focused on the model and algorithm of measure station selection and measure assignment. In the active measurement, we introduced the measure model based on link usage cost, make full use of detection results to reduce the number of measure packets and reduce the measure cost. Iteratively update measure assignment to satisfy the dynamic network environment. For the passive network measurement, we introduce flow conservation law and deduced the station selection problem into weak vertex cover problem. Using greedy algorithm to find result set firstly, and then backtrace to the result set ro remove redundancy nodes, at last we got less measure nodes. Finally, we simulated the algorithms above, through comparison with other algorithms to prove that the algorithm in this paper obtain a better station collection and lower measure cost. We also discussed the collection of measure information and the practical application.