Research And Implementation Of A Network Measurement System Oriented To Overlay Network

With the development of the network and the expansion of the network scale,a variety of new network technology and applications appeared,as well as many overlay network technology,a lot of overlay network applications appeared.Overlay network is built on the existing network architecture,by adding additional,indirect,virtual network layer to improve the performance of the lower layer network.In overlay network,one hop route may correspond to multi-hop route,so the overlay network can also simplify the network topology.It benefit us a lot but bring some difficulties to manage the overlay network.As a result,it is hard to measure the overlay network with the traditional network measurement method.In this paper,we combine the overlay network with SDN(Software-Defined Network),to establish the new network architecture.We proposed a new measurement system called OverlayMon oriented to overlay network which can measure the running overlay network.OverlayMon can measure the network in different granularity by the flow statistic in OpenFlow and then implement the overlay network measurement system with the result statistics.The main contents of this paper are as follows:1.Construct a software-defined network oriented to overlay networks:To realize the network measurement oriented to overlay network,we construct the overlay network by LISP(Locator ID Separation Protocol)protocol,simply the network topology and establish the experiment platform.Besides,we separate the logic control ability from the data layer by programmable switching device NetMagic with OpenFlow protocol.2.Collaborative flow statistics collection on the data plane of the overlay network:Since a traffic is counted on multiple switches,if the flow statistics is polled every times,the redundancy of the statistics will occur,and the measurement resources will be wasted.In this paper,we design a reasonable collection load allocate algorithm BFLA,to locate flow statistics collection task to the specified switch.3.Design and implement of the network measurement system oriented to overly network which called OverlayMon:the system needs to poll the flow statistics and measure the network performance to measure and manage the running network,it is consist of three modules,which are FlowPollingModule,PerfMeasureModule and VisualizationModule.FlowPollingModule is the basic module of OverlayMon,it collect the flow statistics on data plane by collaborative flow statistics collection algorithm BFLA;PerfMeasureModule is the module which carry out the measurement task and calculate the measurement result;VisualizationModule is responsible for presenting the measurement result to users by RESTful APIs of controller with charts and tables.