With the growing popularity of the VoIP technology there are more and more communication networks established, which are moving away from the usage of the traditional telephone networks and change to use IP-based networks. This change makes them cheaper to operate. They can be easily adjusted and upgraded thanks to the modern technologies used in them. In this Master’s thesis I am presenting the transfer of digital speech in a microcontroller managed environment, from the transformation of the analog sound to electrical signal, through digitalization (analog to digital conversion and modulation) and transmission of this signal, as far as to the demodulation and digital to analog conversion. After this I am going to present the different kind of IP-based networks developed for such purposes, their network devices, after that the standard protocols of the VoIP its characteristics and quality parameters (QoS). At the end I am going to describe the steps needed to realize a simple IP-based network using a client-server based architecture with the help of microcontrollers and other tools, which is responsible for the transmission of human speech over the network. I am making the configuration possible using a web server, where the parameters, which are effecting the voice transmission, and the IP addresses of the devices (source and target) can be set. At last I am investigating the operation of this network using tests, than I am going to describe it with the corresponding VoIP quality parameters.