Control who connects
Control publisher and receiver access with Stream IDs or peer-IP rules. Set a matching SRT passphrase when encryption is enabled.
Callaba · Cloud & self-hosted
SRT Server software for live video
Receive SRT streams from encoders and production tools. Check connection health, control access and route feeds to receivers from your browser. Add recording, Multiview or mixing when your production needs them.
Run in your AWS account or on Linux infrastructure you operate.
Live SRT demo
Try a live SRT connection
Create a temporary connection for one hour. Send your feed to the publisher address in Caller mode, leaving Stream ID empty. Watch it in Multiview below, or connect your receiver to the receiver address in Caller mode.
Ready to create
Server controls
Monitor SRT connections and server logs
See which publisher is connected, inspect its bitrate and RTT, and find connection events without leaving the dashboard.
Check the network path
Inspect bitrate, RTT, packet loss and connected peers before changing the receiver or the encoder.
Find connection errors
Open Show logs from the server settings. Pause updates, search by time or message, and export the events you need.
Own SRT server
Make the first connection
Choose how your encoder and receiver connect. Replace the placeholders with the values shown in your Callaba dashboard.
Host & port patternTwo distinct UDP ports: one publisher port and one receiver port. Stream IDs are deliberately empty.
Publisher address
srt://example.invalid:YOUR_PUBLISHER_PORT?mode=callerUse the publisher UDP port. Leave Stream ID empty for this separate-port pattern.
Receiver address
srt://example.invalid:YOUR_RECEIVER_PORT?mode=callerUse the distinct receiver UDP port. Leave Stream ID empty here too.
Prepare the server
In Streaming servers → SRT servers, create the listener and reserve the UDP port or ports. In Streams, permit an empty Stream ID for the intended publisher and receiver roles.
Configure both endpoints
Set the encoder and receiver to Caller and paste their respective address. Caller and Listener describe who initiates the session; they do not describe media direction.
Check video and audio
Start the source. Confirm the publisher and incoming bitrate in Statistics, then check the picture and listen to the audio at your receiver.
Encoder and receiver setup
Connect an SRT-capable source
Use the SRT output of your encoder or production application. Enter the publisher address and connection settings from Callaba, then check the container, video codec and audio format supported by your receiver. These guides cover the application-specific settings:
Connected modules
Use your SRT sources in Callaba
Forward a finished programme with restreaming, or use the mixer to combine sources into a new one.
Monitor
Watch sources side by side with audio meters and stream information in Multiview.
Explore MultiviewRoute
Send a finished feed to receivers or restream it to YouTube, Facebook and Twitch.
Route and restream videoRecord
Select the incoming stream as the source for a recording job.
Record an SRT streamMix
Combine SRT sources with other inputs. Prepare scenes in Preview, then take them to Program.
Mix SRT sourcesChoose where it runs
AWS or your own Linux server.
Choose the infrastructure you operate. Configure SRT through the browser.
Deploy in your AWS account
Review current software pricing and subscription terms on AWS Marketplace. EC2, storage and data transfer are additional infrastructure costs.
Deploy on AWS ↗Install on your Linux server
Use a supported Linux host, VM or private cloud. Follow the current installation guide and license the module units your workflow needs.
Install self-hosted →Capacity planning
Allow for streams, processing and storage
Count simultaneous sources and destinations. Leave network capacity for retransmissions and disk space for recordings. Multiview, mixing and transcoding add processing load beyond forwarding the same encoded feed.
Connection checks
Troubleshoot an SRT connection
The encoder will not connect
Check that the server is enabled, its public address and publisher UDP port are correct, and the firewall, NAT or AWS security group permits the traffic. Then check the permitted Stream ID and any passphrase on both ends.
Look for connection attempts in the event history and Show logs before changing codec settings.
Connected, but no picture or audio
First check that incoming bitrate is present. Confirm the receiver port or paired receiver Stream ID selects the intended feed. Then check its container, video codec and audio tracks against the receiving application.
Browser viewing needs a compatible playback path; browsers do not play a raw SRT URL directly.
The picture breaks up or the stream drops
Compare bitrate, RTT and packet loss over the same interval. Check uplink capacity and retransmission headroom, then review the latency setting. A larger buffer does not fix a consistently undersized uplink.
Export the matching server logs to correlate disconnects with source or network events.
SRT Server questions
Do I need a Stream ID?
Leave it empty for the separate publisher and receiver ports used in the demo. On a shared listener port, use paired publisher and receiver IDs. See the two connection methods.
Can I send an SRT feed to YouTube or Twitch?
Receive the source in Callaba, then create a restreaming task with the destination’s stream URL and key. Match the video and audio settings required by that platform.
Can I mix multiple SRT sources?
Yes. Add SRT sources to the AV Mixer, build scenes in Preview and take the next scene to Program with CUT or FADE. Each camera or other mixer input uses one unit. See current Mixer-input pricing.
How does Callaba fit among SRT server options?
Start with who will operate the server and what must happen after ingest. Hosted services such as Castr and IN/OUT-SRT, open-source servers such as MediaMTX and SRS, and Windows software such as SRT Mini Server suit different operating models. Callaba runs on AWS or your Linux infrastructure, with browser controls and connected video modules.
If your main task is routing between endpoints, also explore the SRT Gateway workflow.
API access
List your SRT servers with curl
This read-only request returns configured SRT servers. Replace the host and API token with your server’s values; the request does not change its configuration.
List SRT servers with curl
curl --request POST 'https://YOUR_CALLABA_SERVER/api/srt-servers/getAll' \
--header 'x-access-token: YOUR_API_TOKEN' \
--header 'Content-Type: application/json' \
--data '{"limit":10,"skip":0,"sort":{"server_created":1}}'Ask AI
Connection guide and technical referenceModes, ports, latency, access and troubleshooting
SRT connection reference: ports, Stream IDs and latency
A practical SRT server reference for configuring separate ports or paired Stream IDs, checking transport health, setting latency, and diagnosing a live…
Use SRT for the contribution leg
An SRT server, or SRT live server, is the configured endpoint for an SRT contribution session. SRT runs over UDP and provides connection modes, recovery and optional encryption; the SRT protocol draft describes the transport.
Caller opens a session and Listener waits for it. Those labels do not set media direction: configure the publisher or receiver role in the relevant endpoint or downstream job.
Keep the access pattern consistent
Create the server under Streaming servers → SRT servers. Use Streams to allow publisher and receiver access, then use the host and assigned UDP port or ports from that server.
For separate ports, reserve one publisher port and one receiver port; blank Stream IDs are valid in the Streams entries and endpoint URLs. For a shared listener port, use paired publisher and receiver access entries with the same server code and Stream ID, plus the publisher/… and receiver/… prefixes. Choose one pattern for a test rather than mixing the identifiers.
Open the selected UDP port or range on the host firewall and network edge. A Caller behind NAT can make an outbound connection to a reachable Listener; test from the real source network. If encryption is enabled, set the same passphrase at both endpoints.
Test with FFmpeg
Examples for a server configured with separate publisher and receiver ports and blank Stream IDs. Replace the host, assigned ports and input file. The FFmpeg SRT protocol documentation defines these URL options.
Publish a local MPEG-TS file
Command
ffmpeg -re -stream_loop -1 -i input.ts -c copy -f mpegts "srt://YOUR_CALLABA_HOST:YOUR_ASSIGNED_PUBLISHER_PORT?mode=caller&latency=200000"Receive from the receiver port
Command
ffplay "srt://YOUR_CALLABA_HOST:YOUR_ASSIGNED_RECEIVER_PORT?mode=caller&latency=200000"In FFmpeg, latency=200000 is a 200 ms example because the option uses microseconds. Set production latency from measured RTT, loss and the permitted end-to-end delay; see the SRT latency guide.
Preflight the path you will use
- Test from the source network, with the hostname, UDP port, access pattern and passphrase planned for the event.
- Verify the selected stream’s destination picture and programme audio, not only the incoming session.
- Save the active configuration and record matching log times from source, server and destination.
- Test the failover procedure only when the event will use it, including its destination behavior and operator handoff.
Set realistic operating limits
SRT latency is a transport recovery buffer, not the whole glass-to-glass delay. Capture, encoding, receiver buffering, decoding, packaging and player buffering also add time. Measure the complete path before reducing buffers.
Plan network and host resources for concurrent streams, measured bitrates, retransmissions, monitoring and enabled downstream jobs. Before a long event, observe the full planned load long enough to reveal queueing, resource contention, or unstable source connectivity. A main/backup transport route can preserve connected receiver and puller sessions through a switch; test its feeds, buffers and destination behavior before relying on it during an event.
More setup guides
Deployment and pricing
Keep the base platform included. Pay for the video work you run.
Dashboard, media management, internal disk and connected storage controls, domains and SSL, cluster management, and supported configuration migration are part of every Callaba deployment. Add functional units only where your live workflow needs capacity.
Included without a separate unit
Control and observationDashboard, UI, and system and module status.
Media and storage controlsInternal disk by default, with connected storage when needed.
Domains, SSL, and configurationDomain controls, SSL, cluster UI, and supported configuration migration.
Two payment models for the modules you select
On-premises and self-hosted use the same modular license. Start with the functional capacity your workflow needs.
AWS Marketplace uses hourly software pricing. Choose the smallest C5 instance that covers the busiest part of the workflow.
Callaba software is not separately metered by bandwidth or storage. Infrastructure, network, egress, storage, and CDN charges remain with their providers.
* The trial applies to Callaba software. AWS infrastructure is charged separately. See AWS Marketplace for current trial and subscription terms.
Ask AI
Try it with a real feed
See whether Callaba fits your SRT workflow
Open the live Multiview demo, launch Callaba on AWS, or install it on your own Linux server.