Avaya's product line starts with a voice call that has video and moves up from there to familiar videoconferencing via USB cameras (its Windows-only Video Telephony Solution product), and then to the 1X Communicator system that can connect a user into a full telepresence meeting.
Cisco also has an offering for the sub-immersive market, announcing recently a system designed to be used in a multipurpose conference or team room, not in a telepresence room built from the ground up. Unlike familiar videoconferencing systems that use fixed cameras or even computers' built-in cameras, Cisco's CTS 1300 system allows you to switch among three cameras; the system has just one screen and one video processor. The bandwidth requirement is 1.5Mbps, but the frame rate is just 5 frames per second (for context, a TV displays at 30 fps).
Of course, there are plenty of quick-and-dirty videoconferencing services available that also use USB and built-in cameras, such as Adobe Connect Pro, Cisco WebEx, Skype, and Yuuguu, plus the instant messaging-based video chat utilities that come with Windows and Mac OS X.
Read more about networking in InfoWorld's Networking Channel.