[wkat4242]

It's not proper call support because the standardisation is a mess. Some carriers don't even support it until now, many refuse to allow it on phones they did not sell etc.

It should have been in the standard from the get go, strictly defined so there's no different standards to check and certify. They should all work the same so there's no need for that.

The lack of standardisation is causing huge problems in countries deprecating 2G and 3G like Australia where people have to throw away perfectly good phones because they're not VoLTE capable according to their provider (and the government mandating that phones without voice service must be banned)

Just like 2G and 3G.