Covers Teradek Core (corecloud.tv), the cloud video management platform that sits between a Teradek encoder and its destinations. Use this guide when your encoder publishes to Core rather than directly to Recast.
If your encoder can reach Recast on its own, it should — go to the VidiU guide or your encoder's own guide instead. Core adds a hop, a subscription and a second thing that can fail.
Core is not an encoder. It ingests your encoder's feed and republishes it, so the path to Recast has two legs:
Camera ─▶ Teradek encoder ─Teradek transport─▶ Core ─RTMP(S)─▶ Mux ─▶ Recast
Recast credentials go into Core, not into the encoder. The encoder only needs to reach Core.
SRT earns its place on an unreliable first mile — a venue wifi, a bonded cellular uplink. That leg here is camera to Core, and Teradek already covers it with its own bonded transport. The Core to Mux leg is cloud to cloud over reliable networking, where SRT buys very little and adds a passphrase, a key length and a latency value to get wrong.
Send RTMP(S) from Core. The packet-loss protection you wanted is already being applied on the leg that needs it.
And if you have a Prism, consider skipping Core entirely. Prism encoders have a full SRT stream mode of their own, so a Prism can send SRT straight to Recast — one leg instead of two, and no subscription. See the Prism guide. Use Core when you want what Core adds: multistreaming, remote management, recording, transcoding, or bonded cellular, which needs a Teradek endpoint to reassemble and so cannot go direct to Recast.
Third-party software can publish into Core over RTMP, SRT or MPEG-TS, but that is a paid add-on. If OBS or vMix is your source and you have no other reason to use Core, send it straight to Recast.
In Recast for Business, open Stream Inputs and choose + Stream Input. Pick RTMP or SRT — the choice is fixed once the input is created.
Recast then shows the values Core needs. Copy them from there rather than retyping them:
Note that an SRT input labels its credential STREAM ID, not Stream Key. It is the same value, under the name SRT uses for it.
Then confirm all three of these, or your stream will be refused:
A new stream input is switched off. Recast switches it on only when it is attached to a live, non-draft video.
Set these on the encoder, not in Core. Core republishes what it receives.
Use no more than 50% of your measured upload bandwidth on the camera-to-Core leg, measured at the venue on the connection you will use.
Avoid Core's transcoder unless you need it. Core can transcode, including HEVC to H.264, but transcoding re-encodes an already-compressed picture and costs quality. Encode H.264 at the settings above on the device and let Core pass it through.
Which URL? Recast displays rtmp://global-live.mux.com:5222/app as your RTMP STREAM URL, and that works. This guide uses rtmps:// on port 443 instead: it is the same Mux ingest wrapped in TLS, so your stream key is not sent in clear text, and port 443 passes through restrictive venue networks that block port 5222. Use whichever your encoder supports.
This is the recommended path from Core.
rtmps://global-live.mux.com:443/appEuropean users can substitute rtmps://eu-west.live.mux.com/app. If Core will not accept an rtmps:// URL, use rtmp://global-live.mux.com:5222/app.
Use this only if you have a specific reason to prefer SRT on the Core-to-Mux leg. Read [how this fits together](#how-this-fits-together) first — for most setups RTMP(S) is the better choice.
srt://global-live.mux.com:6001pbkeylen 16)The defaults are already right. Teradek's SRT settings default to Caller, an encryption key size of 128 bits and 500 ms latency — the same values this guide asks for. On most other manufacturers' encoders the key size defaults to 256-bit and has to be found and changed, so this is one fewer thing to get wrong.
Unconfirmed — the passphrase field on Core's channel form. Teradek documents Passphrase and Encryption Key Size on its devices, but its description of Core's Create Channel form mentions only a URL and a stream key/ID. Recast always issues an SRT passphrase and Mux refuses a connection without one. Expect an Encryption toggle that reveals Passphrase and Encryption Key Size, as it does on Teradek hardware. If the form genuinely has no passphrase field, use RTMP(S) instead.
Two legs, two failure points. A stream can be perfectly healthy on one leg and dead on the other. Always establish which leg is broken before changing settings: Core's Dashboard tells you about camera-to-Core, and Recast tells you about Core-to-Mux.
The 30-minute reconnect window protects the wrong leg. Recast holds the slot open for 30 minutes if the connection to Mux drops — but with Core in the path, that is the Core-to-Mux connection. If your camera leg fails while Core stays up, Mux never sees a disconnect. Recast keeps the stream alive and your viewers watch whatever Core is still sending, usually a frozen frame or black.
Multistreaming is free of your uplink. Core can push to up to 10 destinations from one encoder, and it fans out in the cloud. Streaming to Recast and four other platforms costs your venue connection exactly one stream, which is the main reason to put Core in the path at all.
Engines cost money. Hyperion and Helios are around $75/month each on top of the subscription. Third-party encoder ingest is a Helios feature. Price this in before designing a workflow around it.
The VidiU hardware Core supports is discontinued. VidiU Go is end of life; Teradek's current line is Prism. Core itself is current and supported.
Do not chase low latency. Core Share can monitor at around 200 ms, but that is Core's own monitoring path, not what your Recast viewers receive. Recast streams run at standard latency by design.
One protocol per stream input. A Recast stream input is created as either RTMP or SRT and cannot be switched afterwards.
Check the stream input is attached to a video and that the video is not a draft. Core will report a healthy channel while Recast rejects it.
Then wait a full 40 seconds before concluding anything.
This is the camera leg, and nothing you change in Recast will help. Check the encoder's own network, and on legacy Teradek units check the firmware — Teradek recommends 7.3.14 for older generation encoders on Core.
Establish the leg first. If Core shows the encoder dropping in and out, the problem is the venue connection: move the unit, then drop a quality tier. If Core is stable but Recast keeps ending the stream, the problem is the Core channel — recreate it and re-copy the credentials.
You have 30 minutes to reconnect on the Core-to-Mux leg before Recast treats the stream as ended.
Compare the bitrate Core reports receiving with the bitrate the encoder is configured to send. A gap means the camera leg is the constraint — reduce the encoder bitrate. No gap means look at the source signal or Core's transcoding settings.
If Core is transcoding, turn it off and pass through H.264 instead.
Confirm the encoder is producing AAC-LC at 48 kHz stereo, and that the correct embedded audio pair is selected on the device.
Prefer embedded SDI or HDMI audio over a discrete input so audio and video share a clock. Where Core transcodes, check that its output audio settings have not been left at a different sample rate.
Include your Core account and engine type (Hyperion or Helios), the encoder model and firmware version, the channel protocol, and screenshots of both the Core Encoder Details page and the channel configuration. Say explicitly which leg you believe is failing.
More detail: Recast live ingest reference
