Video Conferencing is generally a costly and resource consuming affair. Lately however, increasing bandwidths have driven a shift away from video mixing and toward RTP translation/relaying. In other words: rather than mixing it, just send it all over the network. Skype video conferencing and Google hangouts are both examples of this trend.

Running a bridge that is capable of handling that kind of RTP relaying can be very inexpensive and one can even do it on most modern desktops/laptops. The problem with doing it is bandwidth: few Internet connections would allow streaming video to five or six different participants in the same time.

The Conference Bridge extension (cobri) allows an XMPP client to export the RTP relaying part into the cloud, run it as an XMPP component and control it through a bunch of IQ commands.

This talk is about presenting the "cobri" extension and the sample implementations in Jitsi and Jitsi Videobridge.