[realxrobau]

It was a bug. If the phone was not making VoLTE calls, the carriers were panicking. Instead, the phone was just trying 3g first, it worked, so VoLTE was never triggered.

VoLTE is just SIP. There's no longer two channels, one voice and one data, it's just the same one (and for those that know the REAL technical stuff, please accept that this is a deliberate simplification!).

[chii]

the video mentions that some phones do not use VoLTE to call emergency numbers, which means after the 3G shutdown, those phones might fail this way. This makes carriers likely to block those numbers, and force you to buy new phone.

It sucks that the choice is to shutdown the 3G network.