BT glossary - I

This glossary is here to help you understand some of the acronyms you may encounter in this site. Select a letter below that your word begins with.

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    
Abbreviation Term Definition


A small graphic that provides a link to a computer program.


IEEE 802.6

An access mechanism standard specified by the Institute of Electronic and Electrical Engineers. See also DQDB.



Advanced applications which combine computing and telecommunications.


Information Age

Major advances in information networks and software tools that enable a step change in business, trade and government processes.


Information Technology

Referring to the computers, software and skills associated with processing information.


Information Technology Security Evaluation Criteria

A European standard which defines a number of levels of system security, and the criteria with which to evaluate systems against these levels.


Instant messaging

You can use instant messaging systems, eg, with BT Yahoo! Instant Messenger, to chat and share information and even see your friends and family at any time you like, without incurring additional call costs.


Institute of Electrical & Electronics Engineers

Represents professional electrical and electronic engineers and others. Headquartered in the USA. Also creates standards for communication protocols and computer systems for instance, Ethernet.


Institution of Electrical Engineers

Represents professional electrical and electronic engineers and others. Headquartered in the UK.


Integrated Services Digital Network

This is a wide area network defined by a number of ITU standards. Connection is made in two ways, basic and primary rate.


Intelligent agent

See agent


Interactive Voice Response

A technology that covers a growing range of applications including home banking, teleshopping and talking timetables for travel operators. Users answer simple yes/no questions to make their choice (usually with a touch-tone telephone), giving them access to a very broad range of expert information without the need for human assistance.


International Direct Dialling

Originally called ISD (international subscriber dialling).


International Electrotechnical Commission

A global electrical and electronic standards body.


International Telecommunications Union

A body within the United Nations devoted to the international harmonisation of telecommunications.


International Virtual Private Network

A network used by an international business or organisation to connect its various offices and factories.



A global network connecting millions of computers. Conceptually it's a huge information resource, spread across computers in academic, commercial and governmental organisations around the world. Information can be retrieved from, and added to, by any authorised user, while the system also acts a giant e-mail system. Other attractions include Usenet, a global conferencing system separated by topic where users post messages, queries and answers on thousands if different subjects of interest. To the user there are many attractions. The Internet acts as a single network, without international borders, and once the commands have been learned, the user can navigate the system with no more difficulty than using the telephone. There is no one network known as the internet. Rather, US regional nets and international nets are all inter-connected (inter-networked) together into one great living thing, communicating at high speeds using the TCP/IP protocol.


Internet call waiting

Notification of incoming call when single-line user in calling an ISP. Links between Call Minder and message notification system - links with SMS, pagers etc can be envisaged - with growing sophistication.


Internet domain suffixes

The Internet is structured into domains, each distinguished by a domain name. At the top level, domains like .ORG (non-commercial organisation), .COM (commercial organisation), .EDU (educational establishment) and .GOV (government) apply internationally. Additionally, each country is allocated a top level domain for example .UK for the United Kingdom. Each countrys top level domain is typically broken down to a second level for example .CO.UK for companies in the UK, etc.


Internet Engineering Task Force

International community of network designers, operators, vendors and researchers whose purpose it is to co-ordinate the operation, management and evolution of the Internet.


Internet Explorer

A software program (browser) from Microsoft with a user-friendly interface for accessing and navigating the Internet.


Internet Protocol

An agreed standard protocol across all internet systems. It transports data packets across the Internet. Communication hosts on the internet have an IP Address, also known as a dotted quad or dotted decimal, which uniquely identifies the machine.

IP address

Internet Protocol address

Sometimes called a dotted quad. A unique address consisting of four parts separated by dots, e.g. Every machine that is on the Internet has a unique IP address - if a machine does not have an IP address, it is not really on the Internet. Most machines also have one or more domain names that are easier for people to remember.


Internet protocol, version 6

The next generation internet protocol which offers greater address space, and improved support for quality of service and security


Internet Service Provider

An institution that provides access to the internet in some form. User subscription is the original way of paying for net access but free services, paid by advertising, are becoming increasingly common such as ClickFree and TescoNet.



An intranet is a constrained version of the Internet usually owned and controlled by a single company or organisation. Intranets can still be world-wide, use TCP/IP protocols, and be structured as a collection of networks but the greatest difference is that access is limited to a set of authorised users (usually the employees of the company/organisation) using firewalls and other mechanisms.


IP address

Every computer or device connected to the internet has its own internet protocol (IP) address. IP addresses can be dynamic and vary with each connection or static so the domain name system (DNS) can reliably route traffic to the right destination site.


IP conferencing

A point-to-point non-business service.


IP multicast

A technique that allows information to be sent to many people simultaneously over the Internet, but without sending many copies of the information across any single link in the network.


Integrated Services Digital Network

Integrated Services Digital Network lines predate broadband, offering speeds of up to 128Kbps. Although ISDN services are still available, most homes and businesses will find broadband to be a better value offering.


ISO 9001

An international quality standard, also known as EN 29000 and BS 5750.



A communication service that requires access to guaranteed, regular time slots, such as voice telephony.



The branch of the ITU concerned with radio and television transmission issues, formerly known as the CCIR.



The branch of the ITU concerned with line telecommunications, formerly known as the CCITT.