ID	原文	译文
46706	现有基于虚拟机动态迁移的防御方法存在迁移算法收敛时间长，开销大的问题，	The existing defense approaches based on dynamic migration of virtual machine have long cover-gence time of migration algorithm and high migration cost.
46707	为此，提出一种基于安全等级的虚拟机动态迁移方法。	Hence, a dynamic migration of virtual machine based on security level was proposed.
46708	首先，对虚拟机进行安全等级分类，减少虚拟机动态迁移的数量；	Firstly, security level classification of virtual machines was used to reduce the number of mi-grating virtual machines.
46709	然后采用相应的虚拟机映射策略，降低虚拟机迁移的频率。	Then the corresponding virtual machines embedding strategy was used to reduce the frequency of virtual machines migration.
46710	实验表明，与现有基于虚拟机动态迁移的防御方法相比，该方法能够降低虚拟机迁移算法的收敛时间和迁移开销。	Simulation experiments demonstrate that the proposed approach can reduce convergence time of migration algorithm and migration cost.
46711	为了改变当前 Internet 网络管理复杂度高的局面，提出软件定义网络（SDN, software defined network），通过控制器生成流策略来直接控制数据流的转发行为。	In order to change situation of high management complexity in current Internet, software defined network(SDN) was proposed, which mainly aimed to directly control forwarding behaviors of data-flow by using flow strategies generated by controllers.
46712	随着 SDN 网络部署与实践，研究人员发现控制器在网络中部署位置能直接影响到网络性能。	With the deployment and applications of SDN, research communities found that the controller placement in SDN network could directly affect network performance.
46713	近年来，围绕控制器放置问题的研究已逐步展开，研究内容集中在性能尺度以及搜索算法这 2 个方面。	In recent years, controller placement problem(CPP) has become a hot topic, where performance metric and searching algorithms are important research areas.
46714	结合当前研究现状，对已有的控制器放置问题的研究进行系统性归纳总结，为后续进一步研究提供参考。	Based on current researches, the existing controller placement problem was systematically analyzed and summarized, which was expected to be helpful for the follow-up research.
46715	随着软件定义网络的发展，可扩展性成为软件定义网络面临的重要问题之一。	With the development of software-defined networking (SDN), its scalability has become one of the most important issues of SDN.