Glossary

Application Sharing

Application sharing is a feature that allows two videoconference sites to view and work together on a document, presentation, web site or application. One site launches the application and shares it with the other site(s).

Bandwidth

Bandwidth is a measure of the speed at which electronic data flows along a communication path. In digital communications systems like the ECU network, bandwidth is measured in bits per second (bps) or kilobits per second (kbps).

BRI

Basic Rate Interface. An ISDN connection utilizing 2 64Kbps B channels (bearer) and a single 16Kbps D Channel (Delta).

Bridge / MCU

In videoconferencing, a bridge connects three or more conference sites so they can communicate. A bridge provides the means for multipoint videoconferences.

CODEC

Stands for Coder/Decoder (a telecommunications term) or Compressor/Decompressor (a computer term). A codec is a piece of hardware or software that compresses and decompresses digital audio and/or video.

Far End

The location where the other participants of the videoconference are located. Signal is received to the Near end site from the Far end site.

File Transfer

This feature of the ViaVideo software allows connected sites to transfer files to one another.

Firewall

A hardware- or software-based system that filters network traffic based on a set of rules. Simple firewalls normally block access to specific ports.

Frame Rate

Frequency in which video frames are displayed on a monitor, typically described in frames-per-second (fps). Higher frame rates improve the appearance of video motion. Broadcast TV (full motion video) is 30 frames-per-second.

Full Duplex

Sending data in both directions at the same time. Usually higher quality but requires more bandwidth. In videoconferencing, full duplex will be much more natural and useable. Cheap speakerphones are half duplex, whereas more expensive ones are full duplex.

Gatekeeper

In the H.323 world, the gatekeeper provides several important functions. First, it controls access to the network, allowing or denying calls and controlling the bandwidth of a call. Second, it helps with address resolution, making possible e-mail type names for end users, and converting those into the appropriate network addresses.

Gateway

Gateways provide a link between the H.323 world and other videoconferencing systems. A common example would be a gateway to a H.320 (ISDN) videoconferencing system.

H.323

The latest standard for video compression for videoconferencing that allows a wide variety of videoconferencing systems to communicate.

ISDN

Integrated Services Digital Network- ISDN is a dedicated line that is used in videoconferencing. The high bandwidth of ISDN makes it possible to transmit voice, video, and text between videoconferencing units.

Kbs

Kilobits per second is a speed indicator measuring the amount in thousands of bits per second data travels. Bps is bits per second, Mbps is millions of bits per second (megabits), Gbps is billions of bits per second (Gigabits).

MultiPoint Videoconference

A multi-point videoconference involves three or more locations (sites), all connected at the same time. Each site can see and hear all the other sites.

Network

A network is a communications system between two or more computers. A network of computers located close to one another and (usually) connected by cables is called a Local Area Network (LAN). A network of computers spread over a large geographical area is called a Wide Area Network (WAN). Networking allows computers to exchange and share information.

Point-to-Point Videoconference

Point-to-point refers to a videoconference between two locations (sites).

PRI

Primary Rate Interface. An ISDN connection utilizing 23 64Kbps B channels (bearer) and a single 16Kbps D Channel (Delta). Also commonly called a T1.

Set-Top Videoconference Device

A videoconference appliance which is designed to be placed on top of a TV (hence the name) typically, although this is not the only way to use it. It mostly includes a Pan/Tilt/Zoom camera, and is controlled with a remote. Examples are a Polycom Viewstation, a Tandberg 880 or a Sony PCS-1600.

T.120

T.120 is an ITU-T standard (International Telecommunications Union) for document conferencing. Document conferencing allows two or more people to concurrently view and edit a document across a network.

T.120 is the commonly-used name to refer to a family of distinct standards. Many videoconferencing companies were developing their own implementations of this until Microsoft released its free NetMeeting software. Now, many companies are using NetMeeting, while perhaps enhancing it in some way.

TCP

Transmission Control Protocol. A connection oriented protocol layered on IP that offers reliable communication, flow-control, and full-duplex connectivity.

TCP/IP

Transmission Control Protocol over Internet Protocol. It is the combined Ethernet protocol standard that covers both network and transport layers.

Teleconferencing

Two or more people who are geographically distant having a meeting of some sort across a telecommunications link. Includes audio conferencing, video conferencing, and or data conferencing.

Videoconference, Videoconferencing

Videoconferencing is the use of communication technologies to allow two or more people to see and hear one another in full motion video while being in different locations. It will also allow the sharing of computer applications (e.g., PowerPoint® presentations, document sharing, file transfer, etc.)

People/Titles

Below is a listing of people generally involved with a videoconference:

• Conference Chairperson - This is the person who leads the videoconference and chairs the session.
• Site Coordinator - This is the person that will serve as the main contact for booking videoconference sessions.