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Knowledge document #134

Making telephone calls with FRITZ!Box through a cable modem

With an additional cable modem, you can also use the FRITZ!Box on a cable connection. If you connect your telephones to the FRITZ!Box, you can use all of the internet telephony providers from which you received login information for internet telephone numbers. These can be the internet telephone numbers from your cable provider or also from different internet telephony providers. In addition, you can connect the FRITZ!Box to the cable modem if your cable provider offers telephony through the cable modem.

Note:All instructions on configuration and settings given in this guide refer to the latest FRITZ!OS for the FRITZ!Box.

1 Configuring the FRITZ!Box for internet telephony

Enter the login information for the internet telephone numbers in the FRITZ!Box as follows:

  1. Configure the internet telephone numbers in the FRITZ!Box.

2 Setting up the FRITZ!Box for landline telephony

The following steps are only necessary if the cable modem has a port to which you can connect analog telephony devices and it is enabled:

Connecting the FRITZ!Box

  1. Plug the longer end of the DSL/telephone cable ("Y cable") included with delivery into the socket labeled "DSL/TEL" on the FRITZ!Box.
  2. Plug the black plug on the split end directly into a telephone port on the cable modem or use the black TAE/RJ45 adapter included with delivery.

    Important:With the FRITZ!Box, you can use only one of the ports for telephones. You can connect an additional telephony device, for example a telephone, to the second port on the cable modem. If the plug on the DSL/telephone cable does not fit into the port on the cable modem, refer to your cable provider for a suitable adapter.

Enabling the landline settings

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephone Numbers" in the "Telephony" menu.
  3. Click on the "Line Settings" tab.
  4. Enable the option "Landline enabled".
  5. Click "Apply" to save the settings.

Entering a telephone number

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephone Numbers" in the "Telephony" menu.
  3. Click the "New Telephone Number" button.
  4. Enable the option "Landline number".
  5. Enable the option "one landline number (analog line)" and click "Next".

    Important:You are only asked to select the type of landline (analog or ISDN line) when you configure the first landline number. If you want to change the connection type later, you must delete all of the landline numbers you configured first.

  6. Enter your telephone number and click "Next".

    Note:It may be possible to use both lines of your cable modem with a FRITZ!Box. For further information, refer to your cable provider directly.