关键词: 软件定义网络, 控制层部署, 时延, 链路故障, 粒子群优化算法, 贪婪算法

Abstract: Most of the controller deployment programs in Software Defined Network (SDN) are focused on the propagation delay under normal network state, ignoring link fault state on the delay. To solve these problems, a controller deployment scheme based on delay optimization was proposed. Firstly, based on the worst delay minimization problem under normal network states and multiple single-link fault states, the network state delay was used as the new delay optimization goal to establish a controller deployment model. Secondly, two heuristic deployment algorithms were proposed to solve the above model:Controller Placement Algorithm based on Greedy Algorithm (GA-CPA) and Controller Placement Algorithm based on Particle Swarm Optimization (PSO-CPA). Finally, in order to measure the performance of the solutions, some real network topologies and data were chosen to verify the validity. The simulation results show that GA-CPA and PSO-CPA algorithms can reduce the network state delay in different degrees, thus ensuring that the worst delay in most network states is maintained at a lower range.

Key words: Software Defined Network (SDN), controller deployment, delay, link failure, Particle Swarm Optimization (PSO) algorithm, greedy algorithm