This is part of the new coherence feature - it is NOT WiFi calling.
RON may be able to do some of what WiFi calling can, but when it is a separate app there is no way it can be as seamlessly integrated or reliable.
Update. It appears that they have fixed Rogers OneNumber -- in terms that the iPhone app can now login again.
Though, in standard Rogers fashion for the 911 address (which I had to re-enter):
1) It won't accept a US address. Isn't the POINT of Rogers OneNumber to continue to use your Rogers # and service without being in a Rogers Wireless coverage area. Like in the US where I am right now.
1) So I entered my home address but it won't accept my 911 address where the street name is a number: i.e. '198th Street'. I had to spell it "One ninety eigth street" -- Once again, standard Rogers Toronto-centric and poorly tested.
-- and even more stupidly (i.e. lack of testing), I then received a notification that my account changed -- indicating that I had signed up for Rogers One Number. Though I've been using it for several years.
Of course I don't expect WiFi Calling with iOS8 to work when I get back to Canada tomorrow.
But WiFi calling is working perfectly with my TMobile service though! (The service indicator says "TMobile Wi-Fi" when the standard cell signal is insufficient and a connect can be made via WiFi.)
Only one carrier in the US has it which is T-Mobile. No one else.. So it seems to me that its something that the carriers & Apple need to work on.
Let's not pretend this is an Apple issue: T-Mobile announced they would have it on day one, as did Rogers. The other carriers did not commit to a roll out. This isn't surprising, since there is no upside for the carrier unless the user is on an unlimited plan already.
There'd be a lot more press about this if there were any fuctional issues preventing a roll-out on the other carriers. Further, Rogers would be griping about Apple if it were an Apple issue. I'm just trying to figure out why Rogers would make the bold announcement if they weren't already prepared to deliver.