Fixed Dialing Numbers (FDN)
Fixed Dialing Numbers is a feature in which you can pre-define a list of phone numbers that may be dialed from this phone, and any other numbers are blocked unless a PIN is entered. This feature may be useful when giving a phone to someone else, such as a child, and you don't want them to be able to make phone calls except to a set of particular numbers.
FDN is a feature that requires support from your carrier, who may provide their own web based interface for initially setting it up. Otherwise, you will need to contact them directly.
FDN only restricts calls made using the public phone network, and cannot restrict calls made using apps which route calls over data, or VoIP.
Enable FDN
Enables the FDN feature. This feature requires support from your carrier, who will provide you with an initial code called a PIN2. Enabling or disabling FDN requires entering your PIN2.
Change PIN2
This allows you to change your PIN2 code. In order to change this, you will need to enter your existing PIN2 code.
FDN List
Allows you to specify the list of numbers on the list of numbers that may be dialed. You will need to enter your PIN2 code to be able to modify this list.