Content Steering is a recent addition to both HLS and MPEG DASH standards, enabling dynamic routing of streaming content between different CDNs. Already supported by DASH.js, HLS.js, and several other players, it dramatically simplifies the design of multi-CDN delivery systems. No custom client plugins, DNS redirects, or CMS integrations are needed.

However, the deployment HLS/DASH Content Steering mechanism will require additional server-side elements: content steering servers. Such servers must interact directly and frequently with streaming clients – at a TTL interval of about 300 seconds or less. The faster reaction is required, the higher the intensity of client-server exchanges. It implies a high volume of additional requests and raises questions about reliability, scalability, and operating costs. This talk discusses the design of a mass-scale Multi-CDN traffic optimization system specifically addressing this challenge. The proposed solution reduces the logic on the content steering servers to a stateless operation, in which all state variables become parameters of the client-server exchange. Such design enables steering servers to be deployed very inexpensively at the edge (by utilizing edge functions offered by many CDNs or edge platforms). All “heavy” processing, including analysis of playback statistics across all sessions and optimizations considering business logic, is done by other components in the system. Their operation is separated from high-volume real-time decisions made by steering servers and deployed using a conventional cloud platform. This architecture enables mass-scale deployment of Content Steering functions with minimal additional operating costs. In the end, we will present demo and experimental results studying the efficiency of this system. This technology was submitted as an open-source project to the SVTA alliance. This talk was presented at Demuxed ’23, a conference for video nerds in San Francisco featuring amazing talks like this one.