Jan Janak is a core developer of SIP Express Router (aka SER). Along these years, he dedicated a lot of efforts to develop many modules or core components such as the internal database APIs (v1 which is still mainly implemented by Kamailio-specific modules and v2 which is mainly implemented by SER-specific modules). Jan contributed several tutorials and presentations to introduce use cases of SER and promote the project.
During 2010, Jan conducted a research project regarding green VoIP, results that were useful to show performances of SER and Kamailio in real world usage scenarios.