Session start
DNS picks the first CDN. We publish DNS answers too, through the DNS you already run — that layer stays, and it stays useful. It is simply not where a live failure gets fixed.
Solutions · Redundancy & availability
Mid-stream CDN stitching.
The stream that survives the CDN.
The structural limit
A DNS answer cannot reach a connected viewer.
DNS-layer traffic management routes the next resolution: a new viewer asks where to go and gets the current best answer. That works — for viewers who have not connected yet. A viewer already playing from a degrading CDN holds an answer cached for its TTL, and no fresh DNS response will interrupt the session it already opened. The viewers you most need to rescue are exactly the ones a DNS answer cannot touch.
Mid-session
When a CDN degrades under a connected viewer, the source of the next segment switches to a healthy CDN. The player keeps playing from its buffer. The viewer never moves — the source does.
The mechanism
The switch is invisible by design.
Behind the buffer
The switch lands on a segment boundary behind the playing buffer, so playback never waits on it. No rebuffer is the mechanism, not the aspiration.
Per viewer
One viewer on a failing path switches; the region does not. There is no thundering herd toward the fallback CDN, because there is no herd — only sessions, each with its own answer.
No-switch windows
Around SCTE-35 markers — ad breaks and program boundaries — switching holds. A rescue never lands in the middle of an insertion.
The failover’s failover
And if vidNT fails, nothing happens.
Decisions are published ahead of the request — into DNS and into Content Steering responses served by your CDNs, not by us. If our control plane goes dark, the last good answer keeps serving and playback continues. Multi-CDN with a fallback that does not add a new single point of failure.
- Manifests are served by your CDNs. We are not in the request path.
- The last published answer keeps working when the publisher is unreachable.
- A static fallback path exists beneath the dynamic one.
Rehearse the failure before it happens.
Run a drill against your own stream and watch the switch land behind the buffer.