FRITZ!Box Call Monitor

• AVM FRITZ!Box (any model with call monitor support)
• Linux with bash
• The following tools must be available: awk, cut, curl (for the IoT branch only), grep, ip, nc, gdbus, iproute2/iproute, python3 (optional; for phonebook import)
• For remote/Pi installations: ssh, ssh-keygen, ssh-copy-id
• For systemd service installations: systemd
• Mandatory on remote host: sshd (openssh / openssh-server package), gdbus (glib2/glib2.0-bin/glib-2 package)

In the installer menu, you can press the d key (for dependencies) to see what your system requires. However, checks for the necessary tools are performed automatically during the installation process anyway.

The installer offers the option to install missing tools directly during the setup process, eliminating the need for a restart if anything is missing. This applies to Arch (pacman), Debian/Ubuntu (apt-get), Fedora (dnf), FreeBSD (pkg), and openSUSE/Tumbleweed (zypper). Other package managers are not currently supported; if an unknown package manager is used and one or more of the required programs are unavailable, the installation will be aborted. FRITZ!Box Call Monitor relies on these programs and would simply not function without them.

The installer also checks whether an SSH connection to the remote host can be established and whether gdbus is available there. The package required for sshd might not be installed by default, preventing the SSH connection from being established; however, the installation can still proceed. To use the tool, openssh/openssh-server (for sshd) and glib2/glib2.0-bin/glib-2 (for gdbus) must be installed on the remote host. Otherwise, no notification will be displayed, even if the FRITZ!Box Call Monitor is running.

Preparation for using the FRITZ!Box phonebook

Export the FRITZ!Box phonebook from your FRITZ!Box:

1. In the FRITZ!Box user interface, click "Telefonie". You can access the user interface either via http://fritz.box or via the local IP address of the FRITZ!Box (http://192.168.178.1 in the factory settings).
2. In the "Telefonie" menu, click "Telefonbuch".
3. Select a phone book, click the "Backup" button, and save the phone book as an XML file on your computer.

Important: If the file download is blocked by your browser, click "Keep" in Microsoft Edge or "Keep" in Chrome.

By default, the installer looks for the file ~/.config/fritzbox-callmonitor/phonebook.xml. However, if desired, you will be prompted to specify a different path and filename, but I recommend to save it as ~/.config/fritzbox-callmonitor/phonebook.xml. It makes the installation process a bit more convenient.

During the installation process, the phonebook is converted into plain text and saved at ~/.config/fritzbox-callmonitor/phonebook.conf. This step can also be performed after the installation has been completed. To this end, the installer provides a menu entry that allows you to convert the phonebook without having to go through the entire installation process again.

It is also possible to manually create a phonebook and save it at ~/.config/fritzbox-callmonitor/phonebook.conf. An existing phonebook can be easily edited. The entries should follow this format:

015112345678=John (mobile)
03012345678=Mary Jane (home)
03087654321=Boss (work)

The call monitor on port 1012 is disabled by default and must be activated manually. If you run the installer without having port 1012 enabled, the installer will display a guide how to enable the port and exits.

Method 1: Using a connected phone Dial #96*5* from any phone registered to the FRITZ!Box. You may hear the message "The number you've dialed is not assigned" — this is normal. The call monitor is activated regardless.

Method 2: Using the FRITZ!Box phonebook

1. Open the FRITZ!Box web interface
2. Go to Telefonie → Telefonbuch
3. Create a new entry named e.g. Activate Monitoring with the number #96*5*
4. Enable the dialing aid under Telefonie
5. Dial the entry using the dialing aid

To deactivate the call monitor, dial #96*4* using either method.

You can verify the call monitor is active with:

nc -zv 192.168.178.1 1012

If the connection succeeds, the call monitor is running.

Connection to 192.168.178.1 1012 port [tcp/*] succeeded!

Note: The FRITZ!Box call monitor requires no authentication and transmits data unencrypted. It is only accessible within your local network.

Make the installer executable and run it:

chmod +x install.bash
./install.bash

Installation process

1. Check that all required tools are available
2. Verify that the FRITZ!Box call monitor is active on port 1012
3. Check for an existing installation and ask before overwriting (values ​​from the existing configuration are adopted by the installer and can be adjusted if necessary)
4. Guide you through configuration via interactive input boxes (incl. optional phonebook import)
5. When installing as a systemd service for remote notifications: Check whether gdbus is available on the remote host (a warning is issued if no SSH connection exists or gdbus is not found; the user can proceed or cancel if necessary).
6. Write a config file and generate the appropriate systemd service file
7. Set up SSH keys if needed (for remote installations)
8. Enable and start the service

The installation program offers the option to convert the phonebook from XML to plain text (Option 10) without having to go through the entire installation process again.

Installation Types

Configuration

The installer writes a config file to /etc/fritzbox-callmonitor.conf (system service) or ~/.config/fritzbox-callmonitor.conf (user service):

The following files will be generated during the installation process and then copied as 'fritzbox-callmonitor' to its appropriate directory:

For remote installations the installer automatically:

1. Generates an SSH key pair for the service user if none exists
2. Copies the public key to the desktop machine via ssh-copy-id

The key is generated without a passphrase so the service can connect unattended. To keep the setup secure:

• The desktop machine should only accept SSH connections from the Pi's or server's local IP

• Add the public ssh key on the remote host to:

  ~/.ssh/authorized_keys
  

• Generates ControlMaster file ${HOME}/.ssh/config with saved authentication information on a per-(user, host) basis, which lets you share one connection among multiple ssh/scp/rsync commands. The file content will be:

  Host 192.168.178.XXX
   		User username
   		ControlMaster auto
   		ControlPath ~/.ssh/cm-%r@%h:%p
   		ControlPersist 60s
  

The installer includes an uninstall option in its menu:

• Option 7 — Remove system service
• Option 8 — Remove user service
• Option 9 — Remove IoT services

This stops and disables the service, removes the service file, the executable, and the config file, and reloads the systemd daemon. Any imported phonebook must be deleted manually (~/.config/fritzbox-callmonitor/phonebook.conf).

Non-systemd Systems

On systems without systemd (e.g., Void Linux with runit), the installer automatically detects the absence of systemctl and limits the menu to options for background and foreground operation, as well as phonebook conversion. Service installation options are hidden.

Notifications are sent via gdbus using the freedesktop.org Notifications specification. No additional tools like notify-send or zenity are required.

• Caller name is displayed in the notification body when available (see section Prerequisites)
• Caller number is displayed in the notification body
• Called number is displayed in the notification body

Example notification:

Incoming call

• Timeout set to 10000 ms the blue line represents the timer; notification auto-dismisses after 10 seconds

Screenshot Incoming Call

In case a call was missed

• Timeout set to 0 notification never auto-dismisses when a call is missed

Screenshot Missed Call

Connect and Answered events are skipped (since you should know whether you have conducted a phone call).