D-Link DI-106 Series User Manual page 86

Besides authentication, another application of CLID is to combine
it with callback. For instance, your company pays for the
connection charges for telecommuting employees, and you are
using the DI-106 or DI-106M as the dial-in server. You can turn on
both the CLID authentication and callback options for the dial-in
users. By doing so, all usage are charged to the company instead of
the employees, and your accounting department can avoid the
hassles of accountability and reimbursement.
Once you are finished filling in menu 14.1, Edit Dial-in User, press
ENTER at the message 'Press ENTER to Confirm...' to save your
selections, or press ESC at any time to cancel your selections.
78 Dial-In Configuration