Content Steering: a Standard for Multi-CDN Streaming

DASH-IF Content Steering [4] (to be soon published as ETSI TS 103 998) is a new standard developed by the DASH Industry Forum (DASH-IF), defining means for managing DASH [5] media delivery using multiple content delivery networks (CDNs). At the server-client interaction level, this standard is compatible with the CDN steering features of HTTP Live Streaming (HLS) [1, 6], effectively enabling the same content steering servers to control delivery for both HLS and DASH-based media distribution.

In this presentation, we briefly review the history of this standard's creation, explain its operation principles, and discuss its various features, utilities and benefits. We also review the implementation of this standard in the DASH-IF reference client (dash.js [3]) [8] and several server implementations available thanks to the efforts of the Players and Playback Working Group at the Streaming Video Technology Alliance (SVTA). Specifically, we examine an implementation using standard Web servers and an architecture enabling deployment using edge functions of modern CDNs or edge platforms. We also discuss using CTA-5004 (Common Media Client Data, CMCD [2]) metadata in the feedback to steering servers and the benefits it brings in this context [7, 9].