Video Conferencing Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

ATM
Stands for Asynchronous Transfer Mode that is a high-speed network technology that is based on sending data in packets or cells of a consistent size. Because the cell is small and a fixed size, ATM equipment can transmit video, audio, and computer data over a single network.

Bandwidth
This is the amount of data that can be transmitted at a given time over a channel. Videoconferencing is very bandwidth intensive, the greater the bandwidth, the better the picture and sound.

BRI
A Basic Rate Interface consists of two 64 Kbps B ("bearer") channels to carry voice, video, and data and one 16 Kbps D-channel for control and signaling.
 

Broadband
Is a term used to refer to circuits that have a high capacity and can carry large amounts of data. The term is usually used for T-1 and cable but can also refer to several ISDN’s.
 

Cable Modem
A device that connects your PC to your cable service, which allows the high-speed transmission of data.
 

Codec
A codec (coder-decoder) takes an analog video signal and digitizes and compresses it so that it can be transmitted. The codec also needs to decompress the incoming transmission and convert it from digital to analog.
 

DSL
A Digital Subscriber Line is a high-speed connection over a standard copper wire connection that becomes high-speed through special provisioning (programming). The distance from the telephone company office limits DSL because the digital signal quality degrades over distance.
 

E1
A European format for a digital trunk that is similar to a T1. It transmits a rate of 2 Mbps over 32 channels at 64 Kbps per channel.
 

Ethernet
One of the most widely used Local Area Network (LAN) standards and supports data transmissions of 10 Mbps. There is a newer version called 100 Base-T or Fast Ethernet that supports data transmission of 100 Mbps.
 

Frame Rate
This is the Frequency that video frames are shown. They are usually described in frames-per-second (fps). The faster the frame rate, the better the video image.
 

Full Motion Video
Full motion video is television-like quality with a frame rate of 30 frames per second.
 

GUI
The abbreviation for Graphical User Interface, which uses pictures or icons on your screen to display to make it simpler and easier for a user than learning complicated commands.
 

H.320
A widely used standard for video and audio transmission to be used over ISDN lines.
H.323
The standard for video and voice transmission over an IP network.

H.324
The standard for video and voice transmission over analog phone lines.
 

ISDN
A digital circuit that transmits voice, video, and text. ISDN can come as BRI service that is commonly used for home and small offices, and PRI service that is used by larger organizations. Stands for Integrated Services Digital Network, ISDN is the most popular means of communicating between videoconferencing systems
Both BRI and PRI use B-channels and a D-channel. Each B-channel carries voice video and data and the D-channel carries the control and signaling information.
 

Kbps
Kilobits per second (thousands of bits per second)-a measurement of bandwidth
 

LAN
This is the abbreviation for a Local Area Network, which is a computer network in a defined area such as an office, building or group of buildings.
 

MCU
A Multipoint Control Unit allows customers to have videophone calls take place between multiple locations.
 

Mbps
Megabits per second or millions of bits per second-a measurement of bandwidth
 

Multipoint
Multipoint Videoconferencing is conferencing more than two points. This requires a system that is capable of multipoint conferencing or using a conferencing bridge (an external service that connects multiple systems together.
 

NTSC
The television format used in the United States and Japan NTSC transmits at 525 lines of resolution 60 half-frames per second. Abbreviation for the National Television Standards Committee.
 

PAL
The television format used in Europe. PAL transmits 625 lines at 50 half-frames per second. Stands for Phase Alternating Line.

POTS
Plain Old Telephone Service, common analog phone service.
PRI
A Primary Rate Interface is the ISDN equivalent of a T-1 circuit and used in medium to large organizations. It provides 23 B-channels for data, voice, and other services and a D-channel for the control and signaling information.

The channels can be used flexibly and allocated to videoconferencing applications when needed.
 

PTZ Camera
Stands for Pan, tilt and zoom camera
 

RS-232
The standard interface for serial devices that is used for nearly all modems. It stands for Recommended Standard-232. Most PC’s contain an RS-232 port to support connecting a modem or other devices.
 

RS-449
The RS-449 is a functional and mechanical description of the DB37 (37-pin) connector used on data terminal equipment.
 

SXGA
A specification for a high-resolution video display of 1280 x 1024. Stands for Super Extended Graphics Array.
 

T1
A high capacity, digital line that transmits at 1.544 million Mbps over 24 channels, at 64 Kbps per channel.
 

TCP/IP
Transmission Control Protocol/Internet Protocol is a protocol that can be used on the Internet and other packet based networks.
 

V.35
A protocol that support data communications equipment to support T1/E1, PRI and satellite modems for customer on public or private networks.
 

VPN
The abbreviation for a Virtual Private Network. This is a network that uses the public network to connect to connect the nodes as if it were a private network.
 

XGA
A standard for high-resolution graphics. Stands for extended graphics array.