I'm using htc one 801s. My carrier support hd voice.
My phone checked "only for internet calls".
Q1. What's the internet calls? Is that mean WiFi or data(3g,4g)??
Q2. If I want to use hd voice, what do I check one of 3 options in attached picture.
Q3. What's the difference between "only for internet calls" and "for all calls when data network is available"??