AASTRA SIP-DECT (Release 1.8)-Installation- and Administration Guide EN - Manual (Page 67)

Installation, Administration and Maintenance
Aastra depl-0900/0.4 Page: 67 (104)
To activate a feature access code, select a unique FAC number, activate the
appropriate checkbox and enter an assigned action code.
Afterwards the appropriate action can be performed by dialing the number
“FAC number” followed by the “FAC action code” en bloc from any
subscribed DECT handset.
In the example above a subscribed user can activate the OMM DECT
subscription by dialing “99999*4701#” en bloc.
WARNING: Overlap sending will not supported for FAC. “FAC number” and
“FAC action code” must be entered en bloc.
FAC functions will be confirmed by an audible indication to the user (in-band
tone signals).