Research And Design Of Network Measurement And Traffic Monitoring Systems

With the rapid development of Internet's expansion and diversification, network performance monitoring and management are strongly required. It is very important to understand network traffic characteristics for network management, network planning and network development. The network traffic measurement technology is one way of network measurement. Monitor and analyze network traffic is an effective method to researching the traffic characteristics and getting network status.Firstly, research background of traffic measurement is analyzed, and the significance of traffic measurement is expatiated. Then the technology of network measurement and indicator system is deeply studied. The active and passive measurement method are particularly discussed and compared. In addition, the application of passive measurement method is discussed, the technologies of flow capturing based on hardware and software are summarized and compared in parallel. By using the theory of network flow analysis, Traffic flow measurement Architecture is introduced. A traffic flow model includes meters, meter readers and managers. Meters gather data from packets so as to produce flow data. Meter readers collect flow data from meters. Managers specify real-time data reduction by downloading configuration data (called rulesets) to meters, while specifying the frequency interval at which meter readers read flow data.By the theory of traffic measurement mentioned above and the analysis to the current means of network dataflow measurement, a network traffic monitoring system based on Linux is designed. The design aim and framework of this system are thoroughly discussed. Dataflow collection module, packet analyzing module, data storage module and interface presentation module, composed of the system, are detailed designed. In data packet capturing aspect, the dataflow collection is realized by using the Libpcap of data packet capturing library under Linux and the framework of traffic collection based on multimode. In data packet analysis aspect, the realization is implemented by making use of the data analysis based on sampling. The module focuses on the network protocol analysis. In data storage aspect, the detailed database structure which is used to store traffic data and statistic information is presented in the system. In interface display aspect, B/S structure is used by this system, and JpGraph Library under Linux is used to generate image of PNG format. The network utilization, the packet size distribution and the use of protocol are displayed by using graphics and tables in client. Then this system is applied to the campus network and fulfilled the measurement of the dataflow in campus network. Through the analysis of flow, problems can be found and handled as soon as possible, which consequently provides fundamental reference to the operation of network. Finally, the whole work is summarized and some ideas and pieces of advice are brought forwards for the future work.