Design and deployment of a hybrid CDN-P2P system for live video streaming

TLDR

CDNs and P2P systems are the common techniques used for live streaming, each having its own set of advantages and disadvantages. The paper presents the design and deployment of LiveSky, a hybrid CDN‑P2P live streaming system. LiveSky combines CDN reliability with P2P scalability, addressing dynamic resource scaling, low startup latency, CDN integration, and network‑friendly upload fairness, and its performance was evaluated using real‑world deployment data. LiveSky has been deployed for large‑scale events serving over ten million users in China, and its performance is comparable to a CDN while scaling effectively when user volume exceeds CDN capacity.

Abstract

We present our design and deployment experiences with LiveSky, a commercially deployed hybrid CDN-P2P live streaming system. CDNs and P2P systems are the common techniques used for live streaming, each having its own set of advantages and disadvantages. LiveSky inherits the best of both worlds: the quality control and reliability of a CDN and the inherent scalability of a P2P system. We address several key challenges in the system design and implementation including (a) dynamic resource scaling while guaranteeing stream quality, (b) providing low startup latency, (c) ease of integration with existing CDN infrastructure, and (d) ensuring network-friendliness and upload fairness in the P2P operation. LiveSky has been commercially deployed and used for several large-scale live streaming events serving more than ten million users in China. We evaluate the performance of LiveSky using data from these real-world deployments. Our results indicate that such a hybrid CDN-P2P system provides quality and user performance comparable to a CDN and effectively scales the system capacity when the user volume exceeds the CDN capacity.