"The voice call ends as soon as the FaceTime call connects. The FaceTime call is over Wi-Fi so does not use carrier minutes."
GSM hovor se ukonci v tu chvili, jakmile se sparujou oba klienti FaceTime a dal uz se nebudou uctovat provolane minuty a cela videokonverzace bude probihat pouze po Wi-Fi.
zdroj napr.: zde