Feature Request: WebTransport Support

[ALPSMAC]

I recently ran across the up-and-coming browser standard WebTransport ( https://caniuse.com/?search=WebTransport ) which has some performance benefits over WebSocket, at least in cases where http3 is available.

To the best of my knowledge there's no normative support for WebTransport yet in any MQTT version specification and browser support for WebTransport is still spotty. It's also not clear to me to what extent MQTT's inherent QoS and protocol specification would benefit from WebTransport.

That said, a quick search in the GitHub issues for Mosquitto didn't reveal any open issue about WebTransport, so I figured I'd at least raise the possibility for support. This might be a long way off, but it does look like there's at least some cxx support out there for WebTransport now ( https://github.com/libp2p/cpp-libp2p | https://docs.libp2p.io/concepts/transports/webtransport/ ) that might make integration easier.

Not sure if Mosquitto has an official feature backlog somewhere that might be better suited for this request, or if it would be better to make a proposal to the upstream MQTT specification... if so, my apologies for the issue spam. Just wanted to get the idea on the project's radar... Thanks!

Kind Regards,
Andy