A caller generates automatic connection establishment within the private branch exchange (PBX) to a previously busy party (only internally). If the the other party cannot be reached, the caller can use the callback function.
-In order to activate the function, insert *5 into your key pad. An accoustic confirmation will finalize the activation.
-As soon as the other party is available again, your end device receives a callback generated by the PBX. As soon as you answer the callback, the PBX sends out a call to the number you tried to reach initially.