Anonymous Call Rejection service automatically rejects all calls for which the caller has withheld the calling number. This may be because the caller's line is configured never to send the calling number, or because the caller has dialed an access code to block the number before making the call.
To Enable Anonymous Call Rejection
Lift the receiver and listen for the dial tone.
Dial *77
Wait for confirmation tone that the feature has been enabled.
To Disable Anonymous Call Rejection
Lift the receiver and listen for the dial tone.
Dial *87
Wait for confirmation tone that the feature has been disabled.