With the advent of home broadband and web cams, basic video conference systems are now available to all, but the conference industry has used these systems for many years and fall into these basic types.
The ISDN system uses up to three digital phone lines to send and receive the video and audio signal. In simple terms, the more phone lines that are used, the better the quality of picture and audio.
If a video conference set up is web based, then the VC unit at each site involved in the conference has an IP address, in the same way as a computer in every office or home has. The IP addresses are accessed by a host VC unit to provide a network of units taking the conference.
Each site involved in the video conference needs a display unit called a ‘codec’, and an engineer to run it. In terms of cost, video conferencing is significantly cheaper than satellite links, however the cost of the phone lines or any cost for web links must be factored in on top of the cost of the equipment and engineers.