Note that in Connect 8 there is the capability to communicate with existing video systems out of the box:
Leverage your existing investments in video conferencing solutions including Tandberg, Polycom, and PictureTel by integrating with video telephony devices supporting SIP/H.264. Meeting hosts can now bring live audio/video broadcast streams into Adobe Connect meeting rooms
At the most simple level though, the tutorial below explains how this can be achieved using a video card to translate the stream into Connect
Using Your Videoconferencing System with Connect Pro (Video, 2:01)
Learn how to integrate your existing videoconferencing system with Connect Meeting
Learn how to integrate your existing videoconferencing system with Connect Meeting
http://seminars.adobe.acrobat.com/videoconf
With an on-premise deployment of Adobe Connect, it is possible to configure the Flash Media Gateway (FMG) in Connect to work with a VCT installation. Instructions on this configuration are in the PDF below
Configuring FMG to work with VCT
http://getconnect.adobeconnect.com/p97h1kilhz9/