Line Settings

Under "Telephony / Telephone Numbers / Line Settings" you can configure various settings for your telephone connections.

Location Information

Enter your country and area code prefix under "Location Information".

Instructions: Entering the Location Information

  1. Select "Telephony / Telephone Numbers / Line Settings" in the user interface.
  2. Select your country under "Location Information".
  3. For the "Country code", enter the leading zeros in the first field and the prefix in the second; for instance "00" and "49" for Germany.
  4. For the "Area code", enter the leading zero in the first field and the area code in the second; for instance "0" and "30" for Berlin.
  5. Click on "Apply".


If you disable the "Landline enabled" checkbox, all landline telephone numbers configured in telephony devices, call diversion settings and dialing rules will be deleted.

A landline is a telephone line in the classic, landline telephone network. The alternative to the landline is telephony over the internet (also called internet telephony, IP telephony or VoIP.

Use fixed-line substitute connection

The FRITZ!Box can establish telephone connections automatically over the fixed-line network if no connections can be established over an Internet telephone number.

If you would like to use this function, enable the "Use fixed-line substitute connection" option.

When establishing a connection using the fixed-line substitute connection, you hear an acoustic signal in the telephone (two short tones and one longer tone). The "Fixed Line" LED on the FRITZ!Box lights up.

Note: For calls that you establish using the phone dialer from the call list, the FRITZ!Box does not use any fixed-line substitute.

Voice packets

Various settings for telephony connections are available only in the advanced view of the user interface.

Fax transmission using T.38

Enable this setting if your internet telephony provider supports T.38. The T.38 standard (fax over IP) provides for reliable fax reception and sending over the internet. Fax messages are transmitted in a special protocol rather than as voice signals.

Keep port sharing of the internet router enabled for internet telephony

This setting is available only when the FRITZ!Box connects to the internet via another router. When the setting is enabled, the FRITZ!Box sends IP packets at regular intervals to keep the port forwarding of the internet router active for internet telephony.

Use VLAN for internet telephony

Enable this setting only if you have received a VLAN ID for internet telephony from your internet service provider.

Use additional connection for internet telephony via DSL (PVC)

Enable this setting only if your internet provider supports establishing a second internet connection for Internet telephony (PVC). The values for the ATM settings (VPI and VCI) are supplied by your internet provider.