I could just do screen sharing too. Port forwarding should be the easiest, if it works.
I just tried it on mine and port forwarding on port 9910 does work. I don't think you'd be able to control more than one behind the router because there's no option to select a port in the ATEM Software Control tho.
if you just need a remote computer to control your studio ATEM, then running a VPN server in your studio and getting the client computer on your VPN will work great. That's a lot less involved than the full solution he was talking about.
Yeah IP:port is a pretty typical convention but there's nothing magical about it and the software has to be able to recognize it. If you try typing ":" into the ATEM Software it just doesn't let you type the ":"
Yeah I just accessed my studio ATEM from home over the internet. The problem is the ATEM Software Control doesn't let you enter a port number, so your router can only forward port 9910 to one device on your network. I still wouldn't do this because the lack of authentication.