SRT Connection Manual SRT allows you to send video and audio over the public Internet. It is a point-to-point connection between 2 computers. No additional server is required. SRT at VMIX knows 3 different types

caller

listner

rendezvous

it is important to understand that the three types of connections have NOTHING to do with the transmitter direction.

Caller: the caller computer is the one from which you do not know or cannot use the public IP-address.
Listener: the Listener is the computer from which you know the public IP address.
Rendezvous: In rendezvous mode, both nodes initiate communication. Rendezvous mode is used when both nodes are behind firewalls and enables communication without configuring the firewall.

If you have both computers on the same network, it is possible that only Rendevous can connect.

Requirements:

the public Internet address on at least one page. (Not the one of your computer after the router, but the IP address before. You can find this with a service such as https://www.whatismyip.com or google “what is my public IP” In my case, the address would be 277.277.277.27, for example.

the IP address of your computer after the router, in my case 192.168.10.102

An open UDP port in your router that allows connection to your computer through your router's firewall. wiki Port_forwarding.

In our example we forward the UDP addresses 1935 and 1936.

In our example we use vixVMIX on both sides, at least version 23.0.0.31 The HD version for 60$ should work

Consult your router's manual on how to set up port forwarding. With my router it looks like this

SRT, you know the PUBLIC IP of the receiver side, VMIX to VMIX

so your sender computer will be the caller, your receiving computer will be the listener
ALL IP’s and PORTS are ONLY EXAMPLES

sender side

Enable SRT

Type caller, Port 1935

Hostname is the Public IP of the Receiver-Modem, in this case 277.277.277.27. The public IP adress can be found with “google my IP” or https://www.whatismyip.com(can not be a 4G Modem or Mobile phone, because they don’t get their own Public IP, theyget a Pool-IP, which can’t handle portforwarding.

You can set the latency 4 times the Ping time. If your connection ist not reliable, raise the Latency time. Start with a Latency of 200ms, go higher, up to 30 seconds, for bad lines, lower to 80ms for SUPERlines. You can also set a passphrase, to encrypt your SRT connection, The passphrase has to be set ON BOTH SIDES the same.

Modern Quadro GPUS can handle H265, with H265 (HEVC) you have approx. ¼ more quality with the same bandwith. If HEVC(H265) stutters on the receiver side, raise Latency, if this does not work, your Hardware is not able to handle HEVC/H265. Choose the compression quality of the stream. Over a 4G Modem most computers can deal with 2mbps.

receiver side

in vMix, add Input

Stream Type: SRT Listener and the SAME port, you have choosen on the sender side, and your Router is forwarding this port to your computers IP (in this example 192.168.0.12)

Thats it.
If you dont get an image within 2 seconds, something is wrong.
If you start changing IP’s or Ports, shutdown and restart VMIX on both sides! SRT can have a long memory….