Software-defined networking introduces opportunities to optimize the Internet Service Provider’s network and to improve client experience for the Video-on-Demand applications. Recent studies on SDN frameworks show that traffic engineering methods allow a fair share of bandwidth between adaptive video streaming clients. Additionally, ISPs can make better estimations of bandwidth and contribute to the bitrate selection for the clients. This study focuses on another aspect of network assistance in video delivery: CDN server selection. In a typical framework where the ISP contributes to the CDN selection, the video provider and the network provider interfaces are merged together. Clients connect to the ISP to get the best CDN server candidate for a given video. This exposes client requests to the ISP. However, video providers have been investing large resources for encrypted video provisioning to preserve their client’s information from third parties, especially network providers. The typical approach is not practical due to privacy concerns. In this study, we present a framework called PPNet to allow CDN-ISP collaboration while preventing the ISP’s access to the video request and availability information. Our framework introduces an isolation between the video provider’s and the ISP’s web interfaces. Clients connect to both of the interfaces and deliver information on a need-to-know basis. As a second contribution, PPNet introduces a practical optimization method for CDN selection. Real-time data collection capabilities of a typical OpenFlow network is used as the input for optimization. Congestion-awareness has been the priority. To adapt for changing network conditions, capability of utilizing multiple servers simultaneously for a single video is introduced. Instead of directing each video client into a CDN node, the proposed system performs request routing per video segment. Finally, we present a system prototype of PPNet and show that our multiple-host adaptive streaming method introduces a significant improvement in quality of experience when compared to the state of the art.

中文翻译：

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PP网

软件定义的网络为优化互联网服务提供商的网络和改善视频点播应用程序的客户体验带来了机会。最近对 SDN 框架的研究表明，流量工程方法允许自适应视频流客户端之间公平共享带宽。此外，ISP 可以更好地估计带宽并为客户端选择比特率。本研究侧重于视频交付中网络辅助的另一个方面：CDN 服务器选择。在 ISP 参与 CDN 选择的典型框架中，视频提供商和网络提供商接口合并在一起。客户端连接到 ISP 以获得给定视频的最佳 CDN 服务器候选者。这会将客户端请求公开给 ISP。然而，视频提供商一直在为加密视频配置投入大量资源，以保护其客户的信息不被第三方（尤其是网络提供商）泄露。由于隐私问题，典型的方法是不实用的。在这项研究中，我们提出了一个名为 PPNet 的框架，以允许 CDN-ISP 协作，同时阻止 ISP 访问视频请求和可用性信息。我们的框架在视频提供商和 ISP 的 Web 界面之间引入了隔离。客户端连接到这两个接口并根据需要提供信息。作为第二个贡献，PPNet 引入了一种实用的 CDN 选择优化方法。典型 OpenFlow 网络的实时数据采集能力被用作优化的输入。拥塞意识一直是首要任务。为了适应不断变化的网络条件，引入了同时为单个视频使用多个服务器的能力。所提出的系统不是将每个视频客户端引导到 CDN 节点，而是对每个视频片段执行请求路由。最后，我们展示了 PPNet 的系统原型，并表明我们的多主机自适应流媒体方法与现有技术相比显着提高了体验质量。