Connecting Belabox to your own SRTLA relay

Belabox bonds several mobile connections into one video stream. This requires a receiving end: an SRTLA relay that reassembles the individual streams. Twitch, YouTube and Kick cannot do this. They only accept a finished stream. The following steps switch your Belabox over to your own relay.

Why use your own relay

On the move, the connection drops again and again. A relay compensates for this: it collects the individual streams from all modems, reassembles them and forwards a single stream. If one modem fails, the others take over as long as their bandwidth is sufficient for the configured bitrate.

Requirements

• The address of your relay
• Your stream key, which authorizes you to send
• Your view key, which OBS uses to pull the video

The address, stream key and view key are shown in the customer portal. Treat them like a password: anyone who knows the stream key can send to your relay. Never show these details on stream.

Step 1: Set Relay server to Manual configuration

In the web interface of your Belabox, open Relay server settings and select Manual configuration under Relay server. This is the only option that lets you enter your own addresses.

Step 2: Enter the address and port

Enter the address from the customer portal in SRTLA receiver address, 8383 in SRTLA receiver port and publish/live/YOUR-STREAMKEY in SRT streamid, with slashes and without spaces. Written as a single address, for example for other senders:

srtla://YOUR-ADDRESS:8383?streamid=publish/live/STREAMKEY

Step 3: Check the bonding

After starting, the Belabox should show traffic for each connected modem. If only one modem shows traffic, the second modem usually has reception but no data connection.

Step 4: Connect OBS

OBS pulls the video from the relay, not from the Belabox. Add a source of type “Media Source”, uncheck “Local File” and enter the following under “Input”:

srt://YOUR-ADDRESS:4000?streamid=play/live/YOUR-VIEWKEY

Set “Input Format” to mpegts. Reception always uses SRT, even if your sender bonds connections. The streams are reassembled on the relay. You can use the same address for testing in VLC under “Media → Open Network Stream”.

Step 5: Set up a break screen

Create three scenes in OBS: LIVE for the video from the road, LOW for a weak connection and BRB as a break screen. Without scene switching, OBS shows a frozen or blank image when the connection drops.

If nothing arrives

• No connection: Compare the address, port and streamid character by character. A single missing slash in publish/live/ is enough to make it fail.
• Port 8282 entered instead of 8383: On that port, the relay only accepts plain SRT, so no SRTLA connection is established.
• Connected, but no video in OBS: The OBS path uses play/, not publish/, and the view key, not the stream key.
• Video stutters despite good readings: Often the delay (SRT latency) is too short or the bitrate is too high for the connections. More delay means more buffer. Start with a low bitrate and increase it only once the stream runs stably.

Moblin, IRL Pro and other senders

The procedure is the same everywhere: select a custom relay server, enter the address and port 8383, and set the streamid. Only the field names differ. Senders without SRTLA support send a single stream via port 8282, without bonding but otherwise unchanged.

See also: View IRL streaming plans Setting up IRL streaming from scratch Switching scenes automatically