GSoC/GCI Archive
Google Summer of Code 2011

Jitsi (SIP Communicator), Kamailio and SEMS

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Jitsi (previously SIP Communicator) is an audio/video and chat communicator written in Java. It supports protocols such as SIP, XMPP/Jabber, AIM/ICQ, Windows Live, Yahoo!, Bonjour. It implements a rich set of communications features such as conference calls, Audio/Video Jingle calls on Linux, Mac OS X, and Windows, call transfers, call encryption and many others. The development of Jitsi started out at the University of Strasbourg, France ( but has grown to include contributors from all over the world. Many of them have actually joined after successfully participating in previous GSoC editions. Jitsi is based on the OSGi ( architecture using the Felix implementation from Apache, which makes it very extensible and developer friendly. Just as last year, Jitsi is once again participating with a couple of closely related projects: Kamailio (, which was previously known as OpenSER is one of the most widely deployed open source (GPL) SIP proxies. It is widely known for its ability to handle thousands of calls per second and its many features. SEMS ( is a media and application server for SIP based VoIP services. Because of its simplicity and flexibility it is commonly used with SIP proxies such as Kamailio or SER as one of the build blocks of various complex VoIP systems. Together, Jitsi, Kamailio and SEMS represent an open alternative to proprietary communications systems such as Skype, or Live Messenger. Our communities often work together on various problems and our combined GSoC participation is an excellent way of moving forward with them.


  • Implementing support for wideband codecs in Jitsi In the context of VoIP communication, a codec is a device capable of processing data beforehand so that it will be in a form suitable for transmission through the Internet. As available bandwidth around increases, the major concern of VoIP developers has shifted from using less bandwidth to supporting better quality. This project is about to implement in Jitsi support for wideband audio codecs. Two wideband codecs, SILK and Opus, will be implemented in this project.
  • Spell Checker This project involves creating a Spell Checker plugin for Jitsi which would alert the user in case a spelling error is detected and give the option to correct the error.
  • Wireshark dissector for XMPP XMPP is communication protocol that is based on XML. This project will provide a Wireshark's dissector that will support XMPP.