One odd quirk is that the calling out ringing tone (https://en.wikipedia.org/wiki/Ringing_tone) sounds like the European, Asian, and Latin American ringing tone standard (https://en.wikipedia.org/wiki/File:1TR110-1_Kap8.3_Freiton1.ogg) rather than the UK, Ireland, NZ, and Singapore audible ringing tone standard (https://en.wikipedia.org/wiki/File:UK_ringback_tone.ogg).

No idea on how to set this.