On a BuzzCall

When you receive your BuzzCall, BuzzAlarm, PIR and motion detections, the iOS device receives a push notification when in working mode - pic A or standby mode - pic B. 

Working mode

buzzpush-a

Standby mode

buzzpucsh-b

You will hear a distinct ringtone on your smart device, and see pic as below

buzzcall

Once you have accepted the BuzzCall (pressing the Green call button), then it will take you into the interface as below

buzzcall-2

Press the Duplex talk button to talk to your visitor

buzzcall-3