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- FRITZ!Box 7690
- FRITZ!Box 7590 AX
- FRITZ!Box 7583 VDSL
- FRITZ!Box 7583
- FRITZ!Box 7582
- FRITZ!Box 7581
- FRITZ!Box 7560
- FRITZ!Box 7530 AX
- FRITZ!Box 7530
- FRITZ!Box 7520
- FRITZ!Box 7510
- FRITZ!Box 7490
- FRITZ!Box 7430
- FRITZ!Box 7390
- FRITZ!Box 7360
- FRITZ!Box 6890 LTE
Setting up an external fax in the FRITZ!Box
You can use a fax machine connected to an analog extension (for example FON 1) or the jack for ISDN devices (FON S0) of your FRITZ!Box to send and receive faxes over the internet and/or landline.
Note:All instructions on configuration and settings given in this guide refer to the latest FRITZ!OS for the FRITZ!Box.
1 Enabling fax transmission with T.38
If you use an internet telephone number for faxing, you must enable T.38 (fax over IP) in the FRITZ!Box for fax transmission. With T.38, a special network protocol is used for fax transmission instead of signal tones. This makes transmission significantly less susceptible to interference:
- Click "Telephony" in the FRITZ!Box user interface.
- Click "Telephone Numbers" in the "Telephony" menu.
- Click on the "Line Settings" tab.
- Click "Changing the Settings" in the "Telephony connection" section.
- Enable the option "Fax transmission using T.38".
- Click "Apply" to save the settings.
2 Enabling the fax switch (passive)
If you want to use your analog landline number to receive both telephone calls and faxes, enable the FRITZ!Box's fax switch. The fax switch automatically forwards faxes to a fax machine configured in the FRITZ!Box:
Important:For faxes to be recognized and forwarded, a different device, for example a telephone or answering machine, must accept the call. The fax switch does not recognize calls that are not accepted.
- Click "Telephony" in the FRITZ!Box user interface.
- Click "Telephone Numbers" in the "Telephony" menu.
- Click on the "Line Settings" tab.
- Enable the passive fax switch. If the setting is not displayed, configure your analog landline number in the FRITZ!Box. You can then enable the passive fax switch.
- Click "Apply" to save the settings.
3 Reconfiguring the fax machine
Set up the fax machine in the FRITZ!Box, even if it is connected to the FRITZ!Box via an ISDN telephone system:
- Click "Telephony" in the FRITZ!Box user interface.
- Click "Telephony Devices" in the "Telephony" menu.
- If the fax machine is already displayed in the list of telephony devices, click the (Delete) button for the fax machine.
- Reconfigure the fax machine: Click the "Configure New Device" button and follow the instructions.
- If you cannot select the socket the fax machine is connected to when configuring it, another telephony device was already configured for that socket. Delete that device.
- If the fax machine is connected to the "FON S0" socket on the FRITZ!Box, during setup you will be shown which telephone numbers to assign to the fax machine. If the fax machine is connected via an ISDN telephone system, you must assign the telephone numbers to the port on the ISDN telephone system that the fax machine is connected to.