Enter your Internet telephone number.

If you have a connection with multiple telephone numbers (SIP trunking), enter all telephone numbers. To open additional entry fields, click the "Add telephone number" link.

For each telephone number you can choose any name to appear on the display of your handset whenever a call for this telephone number arrives. The display function can work only if it is supported by your telephone.

Example: You have two telephone numbers. You use the first one for personal calls and the second for business. You assign the display name "Private" to the first telephone number and "Office" to the second. When your telephone rings, then even before answering the call you can see on the display whether the call is personal or business.

Enter the name of your telephony provider's registrar.

So that you remain reachable, the FRITZ!Box has to register your telephone number with the registrar (or SIP registrar) of the telephony provider.

If you call a telephone number within your area code, you generally do not have to enter the area code on the telephone. The prefix is automatically inserted before the number dialed.

There are Internet telephony providers, however, that do not prefix the number.

For this you can enable your area code here. In this case the prefix will automatically be inserted before the number dialed.

The same is true for your country code and for calls within your country's national network. If your country code is not displayed here, enter the prefix first under "Telephony / Own Telephone Numbers / Line Settings".

The "outgoing special rate numbers" refers to calls to service numbers.

Whenever you call a service number, by default the FRITZ!Box will automatically dial the area code. However, for some telephony providers the service numbers must be dialed without a prefix. If your telephony provider is one of them, enable this option.

Enable this option if you use an Internet telephony provider with an American phone number plan (international prefix "011" instead of "00").

Specify which information the FRITZ!Box sends your telephony provider when you suppress your caller ID by enabling the CLIR option in the FRITZ!Box.

Do not enable the suppress outgoing caller ID (CLIR) option itself here. Use the telephone settings under "Telephony / Telephony Devices" instead.

In most cases the preconfigured "CLIR via display name" is the best option. If problems with suppressing your caller ID arise, consult your telephony provider about selecting a different option.

Specify which telephone number is transmitted to the party called during outgoing calls.

If this setting is disabled, the number saved in your account information from the telephony provider will be transmitted.

You can also transmit a different telephone number if your telephony provider supports this feature: Enter the desired number in the "Internet telephone number" field and ask your telephony provider which option must be selected for "Caller ID".

This setting generally has to be enabled along with the "Relay local telephone number in international telephone number format" setting.

Some Internet providers automatically have a second Internet connection established for telephony. However, over this connection you can only make calls using the telephone numbers supplied by your Internet provider.

Enable this option if you have one of these Internet providers, but the telephone number is from a different provider. Then the FRITZ!Box will use the connection you surf with to make Internet telephone calls. No second connection will be established.

You can always use the preset option "only via IPv4".

If you would like to use a different option, contact your Internet telephony provider first to see what options are available for your Internet telephony package.