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Cannot register an IP telephone or app

Registration of an IP telephone or a telephony app (for example FRITZ!App Fon) with the FRITZ!Box fails. The internet telephone number configured in the IP telephone or the app does not get registered. There is a timeout on the telephone. The error either occurs right after setup or during operation.

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

Simply proceed as described below. After each measure, check whether the problem is solved.

1 Updating the telephony app

  1. Update all of the telephony apps on your smartphone. Check the Google Play Store or Apple App Store for updates.
  2. When you have finished updating, switch the smartphone off and then on again.

2 Changing the password for the respective IP telephone

Changing the password in the FRITZ!Box

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephony Devices" in the "Telephony" menu.
  3. Click the (Edit) button for the respective IP telephone configured for the "LAN/Wi-Fi" port.
  4. Click on the "Account Information" tab.
  5. Enter a password that is at least eight characters long.
  6. Click "OK" to save the settings.

Changing the password in the IP telephone

  1. Enter the new password in the IP telephone for the respective internet telephone number.

3 Deleting the telephony app an reinstalling it

  1. Uninstall or delete the respective telephony app from your smartphone.
  2. Download the app from the Google Play Store or the Apple App Store again and reinstall the app on your smartphone.

4 Reconfiguring the IP telephone for the "LAN/Wi-Fi" port

Deleting the telephone

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephony Devices" in the "Telephony" menu.
  3. Delete the respective IP telephone configured for the "LAN/Wi-Fi" port. To do so, click the corresponding (Delete) button.

Restarting the FRITZ!Box

  1. Click "System" in the FRITZ!Box user interface.
  2. Click "Backup" in the "System" menu.
  3. Click on the "Restart" tab.
  4. Click the "Restart" button.

Reconfiguring your telephone

  1. Reconfigure the telephone in the FRITZ!Box.

    Important:Do not use the wizard configure FRITZ!App Fon. FRITZ!App Fon is automatically set up again if you delete the app from your smartphone and reinstall it.