Resolution Identification of Encrypted Video Streaming Based on HTTP/2 Features

With the inevitable dominance of video traffic on the Internet, Internet service providers (ISP) are striving to deliver video streaming with high quality. Video resolution, as a direct reflection of video quality, is a key factor of the video quality of experience (QoE). Since the displayed information of video cannot be observed by ISPs, ISPs can only measure the video resolution from traffic. However, with HTTP/2 being gradually adopted in video services, the multiplexing feature of HTTP/2 allows audio and video chunks to be mixed during transmission, making existing monitoring approaches unusable. In this article, we propose a method called H2CI to monitor resolution for adaptive encrypted video traffic under HTTP/2. We consider the size of the mixed data for identification. Specifically, H2CI consists of a length restoration method to extract restored fingerprints and a fingerprint-matching method for fine-grained resolution identification. The experimental results show that H2CI can achieve more than 98% accuracy for fine-grained resolution identification. Our method can be effectively applied to infer the adaptation behavior of encrypted video streaming and monitor the QoE of video services under HTTP/2.