NDNlive:命名数据网络下的视频直播系统

摘要

命名数据网络(named data networking,NDN)通过将IP网络中以地理位置驱动的信息交互方式转变成为以数据为中心的信息交互模式,为内容分发应用例如视频播放提供了更好的支持.通过利用NDN的命名机制与数据获取模式,设计并实现了基于NDN的视频直播系统(NDNlive),将实时捕捉的视频传输给多用户.与传统的定长切片技术不同,NDNlive将视频流按照应用数据单元(帧)进行切分与获取.同时对于音频、视频和元数据信息,依照其数据属性和生成模式采用不同的数据获取方法.由于帧获取流水线策略提供的灵活性,NDNlive可以容忍小的网络问题.NDNlive被部署在NDN全球测试平台中,实验结果表明,NDNlive可以在全球跨11个时区提供流畅和同步的视频直播流.%By adopting a data-centric information exchange pattern instead of the IP networks ' location-driven pat-tern, named data networking (NDN) offers better support for content distribution applications such as video streaming application. This paper proposes NDNlive, exploiting NDN features such as naming conventions and data retrieval pattern to stream live video to multiple players. Instead of fixed-size segmentation, NDNlive chops video stream into frames which are the application data units (ADU). For the audio, video content and the media metadata, NDNlive uses different data retrieval strategies according to their data properties and different data generation patterns. NDN-live can tolerate small network problems thanks to the flexibility provided by the frame fetch pipelining strategy. It has been deployed over the world-wide NDN Testbed. The experiments show that NDNlive can provide fluent andsynchronized video streaming across 11 time zones in the worldwide.