If the recipient of your call is busy, you can activate the call back function. It establishes the connection as soon as the line becomes available. The call back function only works on fixed network numbers and can only be activated for one number at a time. After 30 minutes it will be switched off automatically.
As soon as the desired recipient is available, your telephone will ring. Pick up the receiver and wait until your connection has been established and the recipient answers the phone.
If the recipient’s line becomes available, the network will wait 10 seconds to enable the recipient to make a call. If no call is made, the return call to you is placed. If your line is busy, the return call will be placed once you are available again. If you accept the return call, the network will establish a connection to the desired recipient and both users will be connected.