Nowadays, the technology for Internet telephony - VoIP is widely used both in the corporate sector as well as in SOHO environments. This is because that the audio or video packet data communications bring not only economic benefit, but also the consolidation of transmission networks.

It is common for most IP telephony infrastructures that in order to reduce the payload, the stream is separated from the rest of the network using virtual LANs, even though, it is desirable to monitor the quality of calls on each node.

The system, offers an elegant way using network probes to measure and monitor speech quality on the route. The measured data are then sent to a central server in the form of Zabbix monitoring server that allows the visualization of the results in the form of network maps. Probes can be installed in the network as a virtual machine image, as well as tarball packages with source code designated for compilation. The ISO image, containing whole Linux distribution is also available, or the system can be part of the SeeSIP (Smart Embedded Solution for IP Telephony) project.

The system is developed mainly within research of the Czech educational and scientific network - CESNET, but the tool can generally be used in any IP telephone traffic.

SeeSIP - Callmon


Simple and fast deployment of the probe and server side. Reliable and accurate results using intrusive measuring methods. Clear visualization of results, including the localization of the probes. Part of a cross-platform solution called SeeSIP.


Measuring the quality of VoIP traffic and QoS optimization of the network. Based on the autonomous probes, PESQ algorithm and Zabbix server. Probes are available as ISO, VM images, tarball packages - multiplatform support. The possibility to monitor call quality using probes already deployed in CESNET2 network. See Live Demo. User is able to deploy his own Zabbix server and make separate measurement topology.