I should add that I didn't try adding the custom framing protocol via the using: parameter in NWConnection.init(from:to:using:). Because even if that worked (which I doubt), I'd still need to inject it into the connection on the receiving (NWListener) side, and it wouldn't help with that.

Unfortunately I could not get it to work. Modifying its parameters instance does not seem to get picked up by the NWConnection after it is initialized. And I could not find another way of injecting my custom framing protocol, so I gave up on it.

Did you figure out what was causing this and how to avoid it? I am working on a QUIC based video streaming thing also (still at the POC stage myself). For diving into QUIC transport issues I have found qlog logging and visualizing the trace using qvis super helpful.

This might be a good starting point: https://developer.apple.com/documentation/visionos/incorporating-surroundings-in-an-immersive-experience

Just filed it as FB12536427

What does 'dropped immediately' mean? I am now calling start() on all incoming connections and was expecting that only one of them would enter the .ready state. But they all do. So do I need to send my own handshake packet from the client to identify which connection is the real one? Or just wait for a short amount of time? In my app I want to establish one working connection, and then shut down the Bonjour listener and browser and start sending video data across the connection.

Will do! Thank you for the fast and helpful reply!

I tried those steps, but no tada for me 😞. Same problem still.

That looks like a separate issue to me. I'd recommend filing a bug report.