7. The method of claim 4 wherein each of the video terminals is interconnected to the telecommunication switching system via a video link and a telecommunication link and the first, second and third control information are communicated via the telecommunication link.
7. The method of claim 4 wherein each of the video terminals is interconnected to the telecommunication switching system via a video link and a telecommunication link and the first, second and third control information are communicated via the telecommunication link. 8. The method of claim 7 wherein the telecommunication link is an ISDN telecommunication link.