Components of a Generic Video Conferencing System:
Video Input: Webcams connected to computers or video cameras to capture the motion of participants.
Audio Input: Microphones to convert the voice of participants into an electrical signal which is then converted into a digital signal during processing.
Processing Unit: A data processing unit performs the function of converting the data into a packet stream for transmission on the transmitting end, and for receiving the network data and converting it into a presentable format on the receiving end.
Transmission Medium: The communication channel over which the data is transmitted from one place to another. It can be a telephone network or a digital internet broadband network. The network also might contain firewalls which are designed to block any kind of unwanted network traffic. Appropriate modules like Session Border Controllers are usually used on the network to detect various kinds of packets and to allow the videoconference packets to pass.
Output Unit: The output terminals are connected to the receiver unit to present the output in a suitable format. These are usually a monitor or screen for displaying the video and speakers to deliver the sound from the other end.
Usually, all the components are present both in the transmission location and the receiving location as communication is bidirectional.