FRITZ!Box 3370 Service - Knowledge Base

FRITZ!Box 3370 Service

Setting up FRITZ!App Fon

With FRITZ!App Fon, you can make convenient calls via the FRITZ!Box using your smartphone as an IP telephone. FRITZ!App Fon can also be used with several FRITZ!Boxes; this means that you can use different FRITZ!Boxes to conduct calls, depending on your location. To do so, you have to register FRITZ!App Fon once with each FRITZ!Box as described here. Once it is registered, you can also conduct calls over a VPN connection. Besides making calls from home, you can then also make calls over the FRITZ!Box from anywhere.

Requirements / Restrictions

  • iOS 10.0 or later or Android 4.0 or later is installed on the smartphone or tablet.
  • A maximum of ten IP telephones (including FRITZ!App Fon) can be registered.
  • Various FRITZ!Box functions cannot be used with FRITZ!App Fon. This includes call transfer, busy on busy, call-back on busy / no response, do not disturb function for individual numbers, the ability to control certain FRITZ!Box functions such as enabling or disabling wireless LAN, loading factory settings, or setting up call diversions.

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

1 Preparations

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

2 Configuring the FRITZ!Box to allow applications to access it

In the factory settings, the FRITZ!Box is configured to allow applications to access it. If you changed the FRITZ!Box's settings, configure it so that it will once again allow applications to access it:

  1. Click "Home Network" in the FRITZ!Box user interface.
  2. Click "Home Network Overview" in the "Home Network" menu.
  3. Click on the "Network Settings" tab.
  4. Enable the option "Allow access for applications" in the "Access Settings in the Home Network" section. If the section is not displayed, enable the Advanced View.
  5. Click "Apply" to save the settings.

3 Setting up a wireless connection to the FRITZ!Box

The smartphone or tablet must be connected with the FRITZ!Box's wireless network when you set up the app (not the guest network):

4 Installing FRITZ!App Fon

  1. Download FRITZ!App Fon from the Google Play Store or the Apple App Store and install the app on your smartphone.
  2. Start FRITZ!App Fon.
  3. If you set a password for the FRITZ!Box user interface, enter the password.
    • If you enabled "login with FRITZ!Box user name and password", enter the user name and password. The user must be authorized to use FRITZ!App Fon. You can edit the access rights of users under "System > FRITZ!Box Users" in the user interface.

FRITZ!App Fon is now automatically configured as an IP telephone on the "LAN/WLAN" port in the FRITZ!Box.

5 Assigning telephone numbers

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephony Devices" in the "Telephony" menu.
  3. Click the (Edit) button for FRITZ!App Fon. When it was installed, FRITZ!App Fon was automatically configured with the telephone's device name on the "LAN/WLAN" port in the FRITZ!Box.
  4. From the drop-down list "Outgoing calls", select the number that FRITZ!App Fon should use for making calls.
  5. Select the numbers that FRITZ!App Fon should react to when you receive calls.
  6. Click "OK" to save the settings.

6 Configuring FRITZ!App Fon for VPN

Configuring FRITZ!App Fon for iOS

  1. Start FRITZ!App Fon.
  2. Tap "More" and then "Settings".
  3. Tap "Select FRITZ!Box".
  4. Tap "Enter the IP address manually".
  5. Instead of entering, enter the local IP address of the FRITZ!Box ( in the factory settings).

Configuring FRITZ!App Fon for Android

If you are using Android 5 ("Lollipop") or higher, you can use FRITZ!App Fon over a VPN connection without having to configure any settings first. The following settings are necessary in Android 4.4:

  1. Start FRITZ!App Fon.
  2. Tap "More" and then "Settings".
  3. Tap the menu key and then "Advanced".
  4. Enable the option "In all networks - Connect to FRITZ!Box even if WLAN is not connected".

When you now start FRITZ!App Fon, FRITZ!App Fon automatically connects to the FRITZ!Box and remains active in the background. This way you can then quickly and easily make calls over the FRITZ!Box. If you also use other telephony apps (such as Joyn) on your smartphone, then you must always start FRITZ!App Fon before you start the other telephony apps because otherwise automatic registration with the FRITZ!Box can fail. If you want, you can also completely close FRITZ!App Fon in Android. FRITZ!App Fon is always open in iOS.