Desigin And Implementation Of Netstream Network Flow Statistics And Analysis System

Under the wave of information, the internet network is filled with the flood of traffic flow which has a wide variety and large quantity at present. The monitoring of network traffic is indispensable and it has become one of the hottest technologies. The monitoring of network traffic can provide a technical support for flow billing, counting the heat of applications and so on, as well can help network managers to get a better grasp of network situation. Driven by the Internet+ and Industry 4.0, the Internet shows explosive growth. Traditional techniques on traffic statistics such as SNMP, port mirroring and so on, cannot meet the need of more detailed management of the network, due to the in- flexible way and the high cost on dedicated servers. Hence, it is absolutely necessary to bring forward a new traffic statistics technology to support network better. The Net Stream technology based on flow statistics emerges.Based on the analysis of the development of network environment and domestic and foreign traffic flow statistics technology, the paper briefly describes the Net Stream network flow statistical analysis system. Firstly,Net Stream system counts the data flow of network by establishing a new flow table or updating the statistical data in the established flow table when receiving a network data flow not counted. Then, the flow tables, which meets the aging condition, is moved to the aging flow statistical cache zone. In the last, the system packages the statistical data of the flow statistical table in the aging flow statistical cache zone according to template format of output packet. At the same time, the flow table is aggregately counted when meeting the condition of aggregate statistics. After the above treatment, the statistical data is sent to purpose server via forwarding process, plus the UDP protocol header and the IP header.Furthermore, this paper analyzes requirement of network flow statistics and flow table aging including mandatory aging, timing aging, aging induced by flow table specifications or statistical count overflow, aging triggered by FIN or RST packets of TCP protocol, aggregate statistics and output of statistical packet. Based on the above functional requirement, Netstream system is designed and implemented, such as the process of configuration information, addition of general flow statistical table, output of general flow statistical table, addition and output of aggregate flow statistical table, sending packet in the FIFO queue, analysis of statistical data and so on. Through the above function's implementations of flow statistics technology, Netstream system achieves statistics and analysis of a large number of data flow in the network communication environment.Finally, we design various test cases in different environments to test the functions of Netstream system composed of routers, test instruments and Netstream devices. The simulation experiments show that Netstream technology is able to provide fast and accurate network traffic statistics in the complex network environment with large flow, and it can meet the stable and reliable statistical requirements of users.