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.
  • IP telephones are configured in the FRITZ!Box such that only domestic calls and calls to emergency numbers are possible. After configuring an IP telephone you can disable this security feature in order to allow international calls.

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 "Configure New Device".
  3. Select "Telephone (with or without answering machine)" and click "Next".
  4. Select the "LAN/WLAN (IP telephone)" port and then click "Next".
  5. Enter a user name. For registration from the Internet the user name must be at least 8 characters long.
  6. Enter a password and click “Next”.
  7. Select a telephone number for outgoing calls and click "Next".
  8. Specify the incoming calls for which the telephone should ring.
  9. Click "Next", check the settings and then click "Apply".
  10. Set up an internet telephone number in the IP telephone for registration with the FRITZ!Box.

Instructions: Setting Up an Internet Telephone Number in the IP Telephone for Registration with the FRITZ!Box.

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


Instructions: Enabling International Calls

  1. Select "Telephony / Telephony Devices" in the user interface.
  2. Click on the "Edit" button next to the IP telephone.
  3. Next to "This telephone may only make outgoing calls to numbers within the country", click on "Change".
  4. Under "Security", click on "Change Selection".
  5. Disable the checkbox next to the desired IP telephone and click on "OK".
  6. Click on "Apply".