Conferendo 

With Conferendo you can do video Calls One-on-One, group video conference with 3 participants seeing each others, and broadcasting for up to 20 other users.

Special mode for distance learning and online education, in which the lecturer sees and hears up to 16 students, whom in their turn, see and hear only the lecturer.

Other features: Screen Sharing, Slide Show, Whiteboard, File Transfer. Secure connection and encrypted traffic.