支持变长间隔网内缓存的软件定义视频流化系统

Variable-Length Interval In-Network Caching Enabled Software-Defined Video Streaming System

为解决大量视频片段冗余传输造成的网络带宽严重浪费问题,设计一种改进的软件定义视频流化系统。基于网络功能虚拟化技术,在网络节点上实现视频缓存和流化功能。通过抽象出可编程的缓存策略模块,部署针对实时传输视频流的变长缓存窗口(VLCW)算法,降低服务器负载。根据不同的用户接入模式自适应调节缓存视频片段长度,提高缓存资源利用率。实验结果表明,在VLCW算法的优化下,该系统服务器负载下降50 %,缓存资源利用率提高3倍~5倍。

In order to solve the problem of network bandwidth waste seriously caused by redundant transmission of a large number of video clips,an improved software-defined video streaming system is designed.Based on Network Function Virtualization(NFV) technology,video caching and streaming functions can be implemented on network nodes.By the abstracted programmable cache policy module,a Variable-Length Cache Window(VLCW) algorithm is deployed for real-time video streaming transmission to reduce the server load.The length of the cached video clips is adaptively adjusted according to different users’ access patterns so as to improve the cache resource utilization.Experimental results show that under the optimization of the VLCW algorithm,the server load of the system drops by 50 %,and the cache resource utilization is increased by 3 to 5 times.