Research On Measurement Of Network Performance Parameter For SDN

With the increasing scale of the network, ISPs need to measure and analyze delay, packet loss, network traffic matrix and other performance parameters in order to make better control of their networks. However, it is usually difficult to equipment deployment and monitor network traffic in real-time in traditional IP network. Most of the time, the measurement process consumes too many resources. Software Defined Networking is a new networking architecture that separates the network control plane from the packet forwarding plane. It enables flexible control of the large and complex network in a concise way. These features make it is possible to implement measuring method which is impossible in the traditional network. This thesis presents low-cost link performance parameter measurement method based on end measurement method in full SDN and hybrid SDN/ IP network to measure network performance parameters.In the measurement of link performance parameter in full SDN scenario, by flexible configuration of SDN flow table, all links in network can be measured using only three entries, which is valuable resource in SDN switch. Meanwhile, only one monitor is required to send and receive the probe packet in the entire measurement process. Moreover, monitor can be accessed to any switch to complete the measurement. It can significantly reduce the cost of measuring, and overcoming the limitation to position of monitor due to distance, security and other factors in real network environment.Since the deployment of SDN device is limited to technology and the cost of equipment, hybrid SDN/IP network will be an important research scenario.In the measurement of link performance parameter in hybrid SDN/IP network, sufficient linearly independent measurement paths can be provided to estimate all link performance with taking full advantage of SDN flow table and controller, which can change forward direction of SDN switch by modifying flow table rules. Moreover, measurement process consumes little TCAM resource same like full SDN measurement. In addition, the more SDN nodes in hybrid network, the less ordinary monitoring will be used. Furthermore, the hybrid SDN/IP measurement method generates few probes in network as well as full SDN.Traffic matrix represents size the traffic network between any two nodes. The current traffic matrix measurement method commonly used is based on traffic routing information.Generally, rules designed for traffic matrix estimation are also used to forward network traffic. Therefore, it is necessary to take traffic management into account by using raffic engineering. Due to the measurement accuracy of traffic matrixand is closely related to traffic routing and aggregation information, it is usually need to change the route of traffic. Traffic engineering also needs to modify these traffic routes. It may cause that current routes can not satisfy these two goals. In response, this thesis presents traffic matrix measurement scheme balancing traffic engineering in hybrid SDN/ IP network. In the constraint of flow aggregation feasibility, the scheme adjusts the egress port of flow entry in greedy strategy to reduce the maximum link utilization at each step without influencing accuracy of the traffic matrix estimation.