A VTC system consists of a Coder/Decorder, or Codec, a camera, a display device and a microphone. The hardware can be integrated into a room or it can be portable, depending on the user’s requirements. A systems integrator like The Audio Visual Company (AVCO) can assist in deciding what VTC setup is best suited for the user’s application.

There are two (2) basic ways a VTC system can make a “call.” The first way is using Integrated Services Digital Network lines, or ISDN for short. This is basically taking data and voice information and transferring them over phone lines. The “sending” VTC codec uses these lines to transfer the information to a “receiving” codec that displays the information onto a display device.

The second way a VTC system makes a “call” is using IP or Internet Protocol. This method of transmission is the most common way to connect a VTC system due to the number of existing IP networks. Using this method of transmission requires that the IP network have sufficient bandwidth to accommodate the VTC system. The method at which sending and receiving the information is basically the same as described above, but the information is sent through the IP network.

Many VTC systems have options that can be installed into the codec to make it a more robust system. One option is having multi-site capability which allows the user to place multiple VTC calls during one session. The number of sites will vary from one manufacturer to another however. Another option is content sharing. This will allow the user to send and receive content from another source, for example, a laptop or a DVD player while in a VTC session.