中文摘要：

软件定义网络中控制层和数据层分离的工作模式为提高网络利用率提供了广阔的空间,作为其核心的控制器技术得到了研究者广泛关注.本文通过分析软件定义网络的典型架构,探讨了控制器在该架构中的核心作用,综述了控制器在可用性、性能、可扩展性及可靠性等方面的研究进展,认为在未来研究中应着重关注SDN基础网络服务功能抽象、SDN控制器性能优化以及将涌现出的新的安全可靠性等方面的问题.

英文摘要：

The separation of control and data layers in software defined networking provides a wide space for the improvement of network available rate. Its controller, a core technology, receives wide attention from many researchers. We address the core function of its controller and surveys the research advances of availability, performance, extendability and reliability of its controller through analysis of its typical architecture, We conclude that we should highlight its backbone network service abstract, controller performance optimization and new-born security and reliability issues in future.