I’m not sure what you mean by fingerprinting and supported protocols. None of that would be present inherently in a UDP stream unless the application included it. As for hiding IP address, that is a valid use case for a TURN server but I’m guessing 99% of TURN server usage occurs only because the NAT hole punch failed.
> by fingerprinting and supported protocols. None of that would be present inherently in a UDP stream unless the application included it.
Much like TLS, both clients offer all the protocols, versions, and media encodings that they support so that they can find a common set that they can use together.
This is standard negotiation when establishing connections in WebRTC and it's obviously fingerprintable information.
You’re talking about WebRTC which may or may not make use of a TURN server. And I assume there are other uses of TURN which are completely unrelated to WebRTC.
Use of a TURN server does not imply hiding of negotiation details. The TURN RFC [1] does not mention anything related to media encodings or WebRTC negotiations at all.