Multi-CDN switching

Multi-CDN switching is the practice of delivering one stream over several content delivery networks at once and moving viewers between them based on live conditions. Instead of betting an event on a single CDN, you keep two or more connected and let the better-performing one carry each viewer.

The defining capability is mid-stream switching: a viewer can move from one CDN to a healthier one between segments, without restarting playback and without the viewer noticing.

Every CDN has bad minutes — a congested peering point, a regional cache miss storm, an edge that browns out during a tentpole event. With a single CDN those bad minutes are your bad minutes. With multi-CDN, the orchestrator routes around the trouble before viewers churn.

For live sports and high-stakes live events there is no second take: the failover has to happen mid-stream, in seconds, not at the next session.

m-cdn is an orchestrator, not a CDN — it never proxies your video. It watches real delivery quality, scores the connected CDNs continuously, and moves viewers using DNS steering (at connection time) and HLS/DASH Content Steering (mid-stream, between segments).

The approach is grounded in the Vimmi patent family: US10432708B2 (server-mediated CDN selection), US10911526B2 (mid-stream switching), and US11470148B2 (client-side cooperation). That family is the legal moat behind doing this the way m-cdn does.

Under the v2.0 architecture (ADR-122) m-cdn deliberately steps out of the data path. The CDNs serve manifests that m-cdn pre-published to them, and steering happens out-of-band. If m-cdn itself goes dark, the stream keeps playing on a sane CDN order — orchestration is an optimisation layer, never a single point of failure.