Connecting an IP Telephone to the FRITZ!Box

You can connect IP telephones with the FRITZ!Box wirelessly or via LAN cable. With connected IP telephones you can:

  • Conduct internal calls with all connected telephones
  • Use the quick-dial numbers and vanity codes from the FRITZ!Box telephone book
  • Make calls via the landline (for this the FRITZ!Box must be connected with the landline)

Various FRITZ!Fon features are not available for IP telephones, including:

  • Fax and data connections
  • Transfer of calls
  • Busy on busy
  • Switching wireless LAN of the FRITZ!Box on and off

Connecting IP Telephones


  • The FRITZ!Box (preconfigured IP address uses an IP address from one of the following IP address ranges:
    • - 192168255255
    • -
    • - 10255255255
  • The IP telephone has an IP address from the FRITZ!Box's IP address range.


  • You cannot register an IP telephone via the guest access.

Instructions: Connecting an IP Telephone

  1. Connect the IP telephone to a LAN port on the FRITZ!Box or connect it with the FRITZ!Box via a wireless LAN. See the documentation of the IP telephone for information about how to set up the wireless connection.

Instructions: Configuring an IP Telephone in the FRITZ!Box

  1. In the FRITZ!Box user interface, select "Telephony / Telephony Devices".
  2. Click on "Configure New Device".
  3. Select "Telephone (with or without answering machine)" and click on "Next".
  4. Select the "LAN/WLAN (IP telephone)" port and then click on "Next".
  5. Enter a password and click on "Next".
  6. Select a telephone number for outgoing calls and click on "Next".
  7. Specify the incoming calls for which the telephone should ring.
  8. Click on "Next", check the settings and then click on "Apply".
  9. Set up an internet telephone number in the IP telephone for registration with the FRITZ!Box as discribed in the following instructions.

Configuring an Internet Telephone Number in the IP Telephone

  1. Once you have configured the IP telephone in the FRITZ!Box, configure a new Internet number in the IP telephone using the following account information:
Account informationEnter the following
Internet telephone number Can be freely selected, since the number is used only for registration with the FRITZ!Box.
SIP Registrar Enter or the IP address of the FRITZ!Box. The preset IP address is
User Name

Enter the user name (3 numerals) to be displayed in the settings of the IP telephone in the FRITZ!Box user interface.

Password Enter the password you defined during configuration of the IP telephone in the FRITZ!Box.
STUN server Do not enter a STUN server.