Re: WebRTC NV use case Mobility and cost of access

wifi/cell is crude, but it's better than what we have now.

Something better would be nice, but how would it be implemented?  Operating systems don't make this info available.

Agree. There is no such general APi for ‘network cost information’ available in the OS.
Would we expect users to go into some browser setting and tell the browser info like this?

Not preferred option but may be necessary to give special users this possibility in the UA- there are in some apps out there giving the user the control to configure this, given that are often aware of this, as I expect they will be also in the future. I have no strong opinion on this “user preference” approach in the UA.

Would anyone ever use such a setting? It seems like something like this would need to be automatic, but I don't see how it could be implemented.

The automatic seem also a bit magical to me. You mean providing the information to the UA? Also, since the cost of stuff is a user experience thing, as is latency, the user would have to be made aware, and preferably in control, of network usage.

I would however like us to considering allowing the app/site to influence this, leaving to the app to acquire the information (with proper user consents of course).