Design And Implementation Of Distributed SDN Network Simulation Platform Based On OpenFlow Protocol

With the development of Network technology,the requirements of Network architecture of unified management and easy maintenance are gradually improved,and Software-Defined Network(SDN)technology arises at the right moment.However,as available SDN hardware devices are extremely scarce and expensive,with the expansion of network scale and the gradual enhancement of network functions,the mainstream SDN simulation experimental platform cannot carry out large-scale SDN simulation experiments,it is necessary to put forward an efficient large-scale SDN topology simulation method and build a simulation platform for large-scale SDN based on it.Using distributed architecture to solve the simulation problem of large-scale SDN topology for network topology partitioning problem.Aiming at the problem of network topology partition in the process,a new algorithm of weight fusion graph partition based on METIS was proposed to solve it.First,the resource demand of the construction of SDN networks mapping relationship between the host server resources,will the actual SDN topology according to the mapping relationship to the figure;Secondly,a weight fusion algorithm based on Metis was designed.This algorithm performed weight fusion of the mapped multiple weight graphs,then divided the fused single weighted graphs,and continuously optimized the partition results.Then,SDN simulation experimental platform was built to integrate the algorithm.The simulation platform not only realized the integration of the weight fusion algorithm,but also had the functions of the mainstream SDN simulation experimental platform in the market.A graphical interactive interface was added to reduce the use threshold.First,using Linux commands space technology,using a process to achieve virtual node simulation work.For Open Flow switch and Open Flow controller,simulation software such as Openvswitch switch and POX controller is used instead of physical object in order to reduce cost.Secondly,to ensure the synchronization among all works nodes in the distributed architecture,in addition to the creation of work nodes,management nodes are also designed to conduct unified management and scheduling for all work nodes.Aiming at the communication problems with nodes,Pyro4 remote invocation technology is selected to implement task decentralization and transmission of simulation results.Finally,in order to reduce the memory consumption when the program runs,the Tkinter graphics library is used to draw a graphical interface with good user interaction.In the test,mainly tests whether the distributed SDN network simulation platform can carry out SDN experiments,and estimates the partition efficiency of the weighted fusion graph partition algorithm by statistical analysis of the CPU occupancy of each working node during the experiment.In the performance test,some comparative experiments were set to evaluate the platform performance by counting the CPU occupancy and the node size of the maximum simulable SDN network topology.The experimental results prove that the distributed SDN experimental simulation platform can well support the large-scale SDN simulation experimental research,and the proposed weight fusion algorithm can be used to partition the large-scale SDN network evenly and effectively.