Question about FRITZ! Box 4040 International

In a pinch, if there is still time, email avm and request the protocol from swisscom beforehand 😀

I haven't tried it myself. The box supports QOS, which should normally be enough. Prioritisation should also be adjustable.
https://avm.de/produkte...

IP TV is included in the specifications. Since I haven't tried it myself, I can't guarantee it. Based purely on the technical specifications, I would say yes, it works.