FRITZ!Box 3390 – Service - Knowledge Base

FRITZ!Box 3390 – Service

Cannot register an IP telephone or app

Registration of an IP telephone or telephony app (for example FRITZ!App Fon) with the FRITZ!Box fails. The Internet telephone number configured in the IP telephone or app is not registered. The error either occurs right after completing the configuration or during operation. The error message "404 not found" may be displayed on the telephone.

Note:The configuration procedure and notes on functions given in this guide refer to the latest FRITZ!OS for your FRITZ!Box.

Simply proceed as described below. After each measure, check whether the issue persists.

1 Updating the telephony app

  1. Update all of the telephony apps on your smartphone. You can check the Google Play Store or Apple App Store to see whether updates are available.
  2. After you have finished updating, turn 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 button (Edit) for the respective IP telephone on the "LAN/WLAN" port.
  4. Click on the "'Account Information" tab.
  5. Enter a password that is at least 8 characters long and does not contain the user name.
  6. Click "OK" to save the settings.

Changing the password in the IP telephone

  • 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/WLAN" 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 on the "LAN/WLAN" 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