It is possible to join more than two participants with Jabber Video!
Connect the first participant then ask them to hold
Connect the second party.
Once the second party joins the conference you will see the ‘Calls on hold:’ popup image in your Jabber client window.
Click the ‘Join All’ link along the bottom of the pop up to join all participants in the same conference.
At the end of the conference remind all participants to disconnect the call at each end as they otherwise will remain in the conference indefinitely.