Help > Telephoning > Call
Call
A Call 
Shows information about the call such as phone number/contact with profile picture.
B Detail bar 
Displays additional information about the call such as call time, call paths and groups involved.
Opens details.
Closes details.
C Action bar 
*Note: Swiping up within the action bar reveals hidden symbols.
Ends the conversation.
Initiates transfer of the call partner (transfer without announcement).
Starts a new call (query call).
Pauses the call (holds).
Resumes the call (reconnects).
Mutes the microphone (mute).
Turns the microphone back on (unmutes it).
Sends DTMF signals (digits in the ring).
*Further help under Call and transfer