软件定义网络中交换机处理时延的仿真

针对目前的网络仿真工具在对软件定义网络(SDN)的仿真过程中，未考虑交换机的处理时延的问题，提出一种处理时延的仿真方法，目的是为了使仿真结果更加真实和准确。该方法首先将交换机的转发处理过程分解为对流表的查询操作和执行不同的动作；然后，利用交换机的处理器频率和访存周期，将查询流表和执行动作转换为处理时间。实验中测量了真实环境中不同配置的交换机处理时延，并与利用该方法仿真出的处理时延进行对比。实验结果表明，利用该方法仿真出的处理时延和真实交换机的处理时延基本一致，该方法能够较准确地仿真交换机处理时延。

Simulation of switch's processing delay in software defined network

In the simulation of Software Defined Network (SDN), the existing network simulation tools usually do not consider the processing delay of SDN switchs. To make the simulation result more realistic and accurate, a scheme to simulate the processing delay was proposed. First, the scheme divided the process of the switch forwarding into two aspects: inquiry operations on flow table and execution of various actions, and then transferred the two aspects into processing delay by using processor frequency and memory cycle. Measurement and comparison were conducted on the processing delay of switches with different configuration in real and simulation environments. The results show that the simulated processing delay of the proposed method is almost close to that in real environment, it can accurately estimate the processing delay of switches.