Snom VoIP Phone - Manual (Page 31)

Advanced Functions
31
By pressing the
key, call completion is activated and the phone
waits for the other party to return to idle.
If you wish to receive and make calls while you are waiting for call
completion, press again to return to the idle screen which now
shows the letters ‘CC’ in the lower left corner. (Pressing “CANCEL”
cancels the call completion procedure.)
When the other party becomes idle, the following window appears:
If you press the
key, the phone will dial the number again in order
to establish a connection to the other party.
On “no response” (CCNR)
When the phone signals “no response” to your call, activate call
completion by pressing the CC key.