面向互动式网络场景再现的流速控制系统与方法

摘要

Interactive network scenario reproduction is an important method for generating realis-tic and responsive traffic workloads. However, due to the complex traffic generation mecha-nisms, controlling traffic volume based on accurate mathematical models in interactive network scenario reproduction becomes a challenging problem. In this paper, we design and implement a volume control system for interactive network traffic replay, and formulate the volume control task as a target tracking problem where the output traffic volume is regulated through adjustment of input traffic volume. We then adopt a function approximator (FA) in our system to generate the desired input volumes. The FA characterizes the mapping that takes system measurements as input and directly produces controls as output. Meanwhile, simultaneous perturbation stochastic approximation (SPSA) algorithm is employed to adaptively estimate the parameters in control. To validate the system and the method we have implemented it and conducted experiments with actual traffic traces. Empirical studies show that our system can track target output volumes ef-fectively under a wide range of network conditions. The performance of the control system is fur-ther investigated in terms of its convergence time, generated input/output traffic volume and tar-get tracking error.%互动式网络场景再现是一种重要的真实网络流量产生方法.然而,由于流量产生过程的复杂性,基于精确的数学模型对该过程产生流速进行控制是一个较为困难的新问题.文中设计实现了一个面向互动式网络场景再现的流速控制系统,并将网络场景再现过程中的流速控制问题转化为目标跟踪控制问题进行求解.该系统采用一种基于函数近似器的流速控制方法,利用函数近似器对系统的输入输出关系进行描述,通过动态调整系统输入流量来对回放过程输出流量进行跟踪.最后,利用真实网络流量实验考察了文中系统和方法在不同丢包、传输延迟以及会话阻断环境下的实际控制效果,并从收敛时间、产生输入输出、控制误差等角度对系统的控制性能进行了分析.