Bandwidth

The data carrying capacity of a communications channel. Often measured in Kbps (Kilobits per second)

bit

A binary digit, a switch used in computer memory, having only two possible values: 0 or 1

Byte

A unit of computer memory, 8 bits, capable of holding the code for one standard character. Can have 256 different values: 0 to 255, or -128 to +127. Unicode uses 2 bytes to represent a single character and is thus able to incorporate the characters of different languages.

Basic Rate Interface – one of the available types of ISDN telephone connections. Quad BRI or QBRI multiplexes 4 standard ISDN lines to be used as a single line

Coder / Decoder, a device or software that converts analogue pictures and voice into or from a compressed digital stream for or after its journey across the network between conferencing sites

Data is processed to remove unnecessary parts of the data such that it can be efficiently reconstituted; the time taken to compress and reconstitute the data is more than compensated for by the reduction in time required to store the data or read it back

Gigabyte: 1024 MB, 2 to the power 30 Bytes (2³⁰ Bytes)

1000 Megabits per second (not 1024 Megabits per second – communications speeds are calculated, historically, in multiples of 1000) – generally applied to a network system and protocol and originally was an abbreviation of the term Gigabit Ethernet which supports a data transfer rate of up to 1 Gigabit per second.

a connection point for devices in a network; any signal entering the hub is promulgated to all other connected ports, as opposed to a switch (see below)

A standard which defines how data and web-enabled collaboration work in parallel with video in a conference allowing endpoints that support this standard to receive and transmit multiple, separate media streams, typically voice, video and data collaboration

A Video Codec for narrow telecommunications channels at < 64 Kbps

H.264 / AVC: A new video Codec offering major improvements in image quality for a given bandwidth (alternatively a requirement of less bandwidth for the same quality). This new standard surpasses H.261 and H.263 in terms of video quality effective compression and resilience to transmission losses, giving it the potential to halve the required bandwidth for digital video services over the internet or 3G wireless networks

 The ITU standard for ISDN conferencing and includes the following standards:

Audio:      G.711, G.722, G.722.1, G.728

Video:      H.264, H.263, H.261

Data:       H.239, T.120

Control:    H.221, H.231, H.242, H.243

 The ITU standard for LAN conferencing and includes the following standards:

Audio:      G.711, G.722, G.722.1, G.723.1, G.728, G.729

Video:      H.264, H.263, H.261

Data:       H.239, T.120

Control:    H.225, H.245

Internet Protocol is a protocol used to send packets of data over the internet or public network for digital communications

IP Virtual Private Networks provide private access to corporate intranets, allowing mobile users, telecommuters, and users in remote offices to access the corporate intranet, which is increasingly running mission-critical applications that everyone in the company needs to access

Integrated Services Digital Network: a global standard for digital dial services. Available in a variety of speeds

International Telecommunications Union, an authority for establishing standards in telecommunications internationally

Kilobyte; 1 KB = 1,024 Bytes = 2 to the power 10 Bytes (2¹⁰ Bytes)

Kilobits per second, used for measuring the speed of communications channels; 1 Kbps = 1,000 bits per second; note that the powers of 2 are not used for communications speeds owing to the different origin of the term

Local Area Network - , a directly connected group of computers generally existing in only one building

Linear Tape Open on the Ultrium 2 recording standard

Megabytes; = 1,024 KB = 2 to the power 20 Bytes (2²⁰ Bytes)

Megabits per second, 1000 Kilobits per second (not 1024 Kilobits per second – communications speeds are calculated, historically, in multiples of 1000) – generally applied to a network system and protocol

Where more than two sites are involved in a (video-) conference. Requires a multi-point control unit either integrated (possibly software) or standalone

Network Attached Storage; an extremely efficient and low cost method of attaching storage capability to a network

Native mode is a term used meaning ‘uncompressed’, i.e. data is saved on a byte for byte basis; see ‘compressed mode’ above

See Virtual Memory

Quad BRI, i.e.  BRI for 4 connections or Basic Rate Interfaces

Redundant Array of Independent Disks; a method of ensuring great accuracy in data storage. Commonly used Small Server levels of RAID are: RAID-0 (striping), RAID-1 (mirroring), RAID-5 (multiple disk striping), RAID-0+1 (striping and mirroring)

Random Access Memory, the main processing memory of a computer, usually measured in Kilobytes (KB), Megabytes (MB), Gigabytes (GB) or Terabytes (TB)

a device to forward data via the best route from one computer network (LAN or WAN) to another

Return To Base, a method of warranty handling

Small Computer System Interface, a method of connecting computer components, such as disk storage, to the computer

Screen Resolution of up to 800 x 600 pixels. (Super Video Graphics Array)

(correctly: a switching hub) a connection point for devices in a network; any signal entering the switch is promulgated directly to the port connected to the specifically addressed computer (established on initial connection), as opposed to a hub (see above)

Terabyte: 1024 GB, 2 to the power 40 Bytes (2⁴⁰ Bytes)

A set of electronics providing text and graphics which may be output to a monitor; may be provided as a single card or integrated into a motherboard

A facility allowing people at a number of remote locations to join a conference and share information

A memory management facility allowing information in memory to be swapped out to alternative storage so that the memory it occupies can be used for other purposes; sometimes referred to as paging

A Virtual Private Network allows organisations to use the Internet or public network (such as an analogue or digital telephone network) for digital communications on a point to point basis

Wide Area Network, a set of groups of computers or LANs usually interconnected and often spread throughout a number of buildings. Often connected via direct telephone links, or via the Internet

World Wide Web, an aspect, or application, of the internet consisting of a massive collection of hypertext pages organised within web-sites, interconnected by hyperlinks and accessible via a browser

Screen Resolution of up to 1366 x 768 pixels. (Wide eXtended Graphics Array), based on the 16:9 widescreen ratio

Screen Resolution of up to 1024 x 768 pixels. (eXtended Graphics Array)