How to configure asterisk for having a Video Conference?

Hi all,

During the last days i tried to configure asterisk for having conference and i succeed. But i’ve just audio conferences.
However there is an option to mark in the meetme application for having video :

exten => 218,1,Meetme(218,v)

But when i connect to the conference i can just talk to other people but i can’t see them…

(For me a videoconference has more than 2 users)
Is there anybody here who has an idea which could help me?

I post my conf files here :