VoLTE with data turned off?

Question

Telecom operators

Will VoLTE calls work with mobile internet turned off?
Or is mobile data required?

An example is a SIM card of a megaphone, VoLTE is enabled in the settings, BUT in the office and at home I turn off mobile data transmission, I use Wi-Fi. The VoLTE icon does not disappear near the network signal in the corner. And at the same time, how calls go - via VoLTE or 3g / 2g

Answer 1

Will not: VoLTE works just over the mobile Internet.

Answer 2

It's called voWiFi, it works on top of wifi. Calls go through it, are charged as if you are in the connection region, but there may be nuances.
It does not work for all operators, not on all devices, it works differently on different combinations of devices and operators and the indication is different. In theory, it works right out of the box, but on individual SIM cards you need to connect through support. Does not work in all regions (SIM connection region).