Call Back

Flexible call-back service

The Call Back Service offers different functionalities if an internal or external contact in unavailable. The following options exist:

  • Call-back reminder with caller’s individual time specification
  • Forwarding to voice mail
  • (Internal) contact will be notified of call-back request
  • Information as soon as (internal) contact is available again

Call-back reminder

A call-back reminder is easily set directly on the phone if a called contact is busy. The call-back list then saves multiple call-back reminders.

The time interval for the display (duration) of the call-back service as well as the call-back interval and the maximum period of the call-back reminder are set-up in the central configuration beforehand. Different call-back profiles are available:

  • Call-back display on no answer
  • Call-back display on busy
  • Call-back display on second call (call waiting)
  • Direct forwarding to voice mail

The active call-back list is accessible to the user at any time. Dialling or deleting an entry can be executed directly in the list.

Forwarding to voice mail

Instead of setting a call-back reminder, the caller may choose to be forwarded to the voice mail and leave a voice message.

Internal call-back service

For internal calls a call-back request can be made if the desired contact is busy. A message will appear on the phone as soon as the contact is available again.

Alternatively, a pop-up may be set which will be shown on the called party’s phone when they hang up. The call-back may be initiated using the simple push of a button (automatic call-back).


  • Hardware
  • Software
  • ICT system
  • Phones

4 CPUs (Cores)
Gigabit-/Fast-Ethernet network interface card
120 GB hard disk for installation
Virtualization supported (VMware & HyperV)

Microsoft Windows 2019 or 2016
NTWphone Server

Cisco Unified Communications Manager 10.x (and higher)

  • Cisco IP Phone-series with display (supported by Cisco)