面向OpenFlow的内容分发网络视频流传输策略
OpenFlow oriented content delivery network video stream transmission strategy

提出一种基于软件定义网络(SDN)的内容分发网络(CDN)体系架构，通过改进OpenFlow的控制器接口，借助可伸缩视频编码的基础层实现无损传输，加强层为增强视频提供尽力而为的传输. 通过多种情景的模拟实验，该体系架构在网络拥塞的情况下，能有效提高峰值信噪比，提供良好的视频传输服务质量.
We propose a new content delivery network(CDN) architecture based on software defined networking(SDN). It improves the interfaces of the OpenFlow controller. With the help of scalable video coding(SVC) on the base layer，the video can be transmitted in a lossless-QoS way，while the enhancement layers routed in a best effort way. Through multiple scenarios simulation experiments，the architecture proposed in the paper can effectively improve the video’s overall PSNR and good video transmission service quality under network congestion