Smartphones nowadays develop at an unbelievable rate. These devices are becoming everyday necessities for more and more people. One of the biggest reasons of this „conquer” is Android, which is the most commonly used mobile operating system in the world. Todays more and more popular social networks are undeniably somewhat responsible for this kind of widespreading of mobile devices. The users of these kind of networks expect to have features such as user presence information and VoIP calls.
The goal of this thesis is to integrate these services to a university social network called HAVER (this translates to Buddy).The thesis, following the principles of software development, begins with defining server - and client side requirements. To satisfy these defined requirements, the thesis investigates th ebest available solutions for VoIP technology. Among all the available solutions it focuses mainly on the free and open source server and client side solutions. Among the examined systems and applications it wants to find and know more of, the best available solution for satisfying the client and server side requirements. The thesis gives a suggestion for a complete server and client side VoIP solution. This is done by the going through all the selected solutions with software development planning and the realization stage. The thesis’s ending element is, the testing phase which is responsible for checking all the functions of the system, and in the meantime goes throught all the functions of the product, thus demonstrating them.