Parent page: Internet and Networking

Zfone {en} is a programme, which encrypts VoIP calls. It can be used with any VoIP software (e.g. Ekiga), because Zfone just does the encryption. This article explains the usage of Zfone with Gizmo. Generally, the encryption only work when both subscribers use Zfone.


The following packages have do be installed:

  • libgtk2.0-dev

  • iptables-dev

At the moment there are no official packages for Zfone, because it is still in an early beta version. To get a download link for Zfone, one has to register here {en} with a valid e-Mail address.

After downloading Zfone, the archive has to be extracted. Zfone can be extracted, compiled and installed using the install script.

sudo ./


Do get Zfone running properly, some kernel modules for IP filtering have to be loaded.

sudo modprobe iptable_filter
sudo modprobe ip_queue

If you use Gizmo, the network setting in gizmo can be set to "automatic". The Zfone configuration file already contains an entry, which enables the monitoring of the Gizmo standard port 64064.

In case you use another VoIP software, you have to change its SIP port to 5060. At least this is the only tip you get from the official web site. Otherwise Zfone will not recognise your VoIP calls.


First of all, the Zfone deamon zfoned hast to be started with super user privileges.

sudo zfoned

Afterwards, the Zfone GUI can be started.


Zfone is now in the state "idle". This means, that it monitors the ports for VoIP calls and it is ready to encrypt recognised calls (Illustration 1).

When a VoIP call is recognised and the call partner uses Zfone as well, the encryption will be activated (Illustration 2).



Illustration 1: Idle state

Illustration 2: Encrypted call with Gizmo

Zfone (last edited 2008-07-24 17:11:15 by localhost)