Neighbor Selection Strategies in the Wild for CDN/V2V WebRTC Live Streaming: Can we learn what a good neighbor is?

A hybrid CDN/Viewer-to-Viewer (V2V) architecture is an attractive solution for HTTP (HLS) and MPEG-DASH-based live streaming providers. It combines a traditional CDN with a V2V overlay for exchanging video fragments, reducing the cost of the CDN while maintaining the quality of experience. This work explores machine learning models to address the key challenge of neighbor selection. Our goal is to predict the connection quality between two arbitrary viewers using features such as locality, access providers, operating systems, past CDN, and V2V throughput. The proposed solutions are validated using an A/B testing approach on our production system, demonstrating a significant improvement in key system metrics compared to the traditional locality-based methods. We observe 17% higher V2V throughput, 26% lower delay, 37% fewer lost chunks, 39% fewer re-buffering, and 20% fewer quality switches.