Proactive Information Dissemination in WebRTC-based Live Video Distribution

Live video distribution represents a significant fraction of the video traffic in the Internet. Its distribution induces heavy costs to serve clients during peak hours. To tackle this issue, the hybrid Viewer-to-Viewer (V2V) mode - where peers cooperate with each other in addition to receiving data from a Content Distribution Network (CDN) - has been proposed to both improve the Quality of Experience (QoE) and reduce the distribution cost. In this paper, we present the improvements we have introduced in a commercial V2V Web live streaming system based on the Web Real-Time Communication (WebRTC) standard. A key challenge faced when designing such a system is the algorithm that governs the client's behavior and should maximize the amount of a data exchanged in V2V mode. A crucial component in V2V Web live streaming is the fast distribution of the video chunks availability in the V2V network. We present in this work our initial reactive approach to distribute the information concerning chunks availability and contrast it with our new proactive approach. We demonstrate the efficiency of the proactive approach on a testbed featuring light clients (browsers) separated using Linux network namespaces, as well as with live experiments. The fraction of V2V traffic for the production environment also improved from 19% in the reactive approach to 37% in the proactive one. Furthermore, we demonstrate that the buffer length of the clients both in the controlled environment and in production is improved, implying a better QoE.