It was time again to re-install my Fritz!Box, unfortunately the box does crash sometimes and only a factory reset brings the broken services back to life (in between those crashes the box actually runs very solid).
So I setup all of my local services and DECT phones and concluded with the setup of my VoIP accounts. While testing ingress calls I noticed a nice HD icon on my DECT phones’ display. The Fritz!Box GUI surely lists my test calls with Codec G.722.
I have tested HD Voice with voipGATE.