I just made a call to my sister in Austin. She uses AT&T because that's all that works in her area but I called using my T-Mobile (MetroPCS) line. To my surprise, the HD Voice was lit up on the display. The call was as clear as calling another T-Mobile customer. When did they get cross network HD Voice working? I must not call enough AT&T customers since this is the first time I have seen it. I can always tell that the other caller is on T-Mobile due to the higher voice quality.



She was using an AT&T iPhone 6 and I was using a LG K7 that was sent to me for testing.