Why does Samsung use wifi to call and how to switch it off?

[Hellick]

Don't get me wrong, wifi calling is not set up on my phone.
I have unlocked att s7 used in T-Mobile.
And when I'm connected to WiFi it uses it for regular phone calls.
Generally it would be OK, but I have two issues with it:
a) when I am connected to a relatively crappy internet (like Starbucks, or far from router) the call quality is poor
b) when I go out of the range of the wifi I was connected to in the beginning of the call, it (the call) disconnects.

Any suggestions?
Thanks

 

[LeoRex]

Open the phone app and check settings... or go into the Settings area and search for WiFi Calling. You can toggle it there. You have three options : 1) use WFC always, 2) Use WFC when the cell connection is poor, 3) Disable

As for the disconnect issue, that SHOULD be handled by the telephony stack... the wifi-mobile handoff is something they are all working on, but it might not be 100% reliable for everyone.

 

[Hellick]

Let me correct myself a little bit: I cannot setup wifi calling in order to access those settings. T-Mobile WFC comes only on T-Mobile devices and I was not able to install it on mine, and att wifi calling (the preinstalled one, the one it tries to access, when I press "wifi calling" in settings) cannot be setup because I'm not in att network anymore... And since WFC is not setup, I am not entirely sure WFC is what's happening...

 

[LeoRex]

OH!! my bad...sorry about that.

WiFi calling is pretty specific to the carrier on many phones. If you have an AT&T S7, it may very well be that it is not compatible with T-Mobile's system. Do you get a persistent notification that calls are being made over WiFi?