Do we have any idea if the iPhone supports VoLTE?
Yes, it does. That's what "HD Voice" is on the iPhone 5. HD Voice requires G.722.2 AMR-Wideband audio, which only LTE can provide without causing too much network congestion.
However, "Allows VoIP" doesn't necessarily mean that this is "VoLTE."
Yes, it does. That's what "HD Voice" is on the iPhone 5. HD Voice requires G.722.2 AMR-Wideband audio, which only LTE can provide without causing too much network congestion.
However, "Allows VoIP" doesn't necessarily mean that this is "VoLTE."
HD Voice on T-Mobile is not VoLTE though. The iPhone 5 does not support VoLTE.