Westbrook Communications

Glossary

A, B, C

ADSL Stands for Asymmetric Digital Subscriber Line. This is a high speed internet connection supplied via your existing telephone line. Standard speeds are 512Kbps downstream and 256Kbps upstream, hence asymmetric, although speeds of up to 2Mbps downstream are possible.

Broadband Generally refers to a high speed internet connection. (The definition of high speed differs depending on who you ask, but generally means speeds of greater than 100Kbps, ie not a standard analogue modem).

D, E, F

DHCP Stands for Dynamic Host Configuration Protocol. It is a means of automatically distributing network configuration information to computers on a network, usually IP addresses. Some ADSL routers support DHCP which makes installation a lot simpler.

EIA Stands for Electronic Industries Alliance. It is a national trade organization that includes the full spectrum of U.S. manufacturers.

ETSI Stands for European Telecommunications Standards Institute. It is an independent, non-profit organisation, whose mission is to produce telecommunications standards for today and for the future. It is responsible for stanadardisation of Information and Communication Technologies (ICT) within Europe.

Firewall A properly configured firewall helps protect your computer from hackers on the internet. Some routers come with built in firewalls, but we strongly recommend that if your computer is connected to the interent via an always on service such as broadband you should install a personal firewall on your computer.

G, H, I, J, K

IEE Institute of Electrical Engineers is a non-profit organisation that represents proffesional engineers. The IEE is also issues regulations for the safe installation of electrical and electronic equipment and takes a leading part in the formulation of national and international standards.

IP Stands for Internet Protocol and is the language used by devices on the internet to communicate with each other. Every device using IP must have an IP address. IP addresses can be recognised as being four numbers seperated with dots, each number being a value between 1 and 255. Devices with public IP addresses are visible to all other devices on the internet, but devices with a private IP address can never be visible on the internet. Private IP addresses take the form 192.168.x.x or 10.x.x.x

ISP Stands for Internet Service Provider. The company which provides you with an internet connection.

L, M, N, O, P

LAN Stands for Local Area Network. A number of computers connected either in the same building or on the same site. It is used to share resources such as the internet, printers and secure data storage. A basic LAN might consist of cabling, switches and routers.

Modem A device which recieves data from the internet and converts it into a format which your computer can understand. If your internet connection is supplied via a cable TV company they will supply a Cable Modem. If your connection is via a telephone line you normally have the option to buy a modem from your ISP or you can supply your own.

NAT Stands for Network Address Translation. This is a method of allowing multiple computers to connect to the internet using the single IP address supplied to you by your ISP. NAT can be carried out using software, but is more commonly a feature of routers.

PSTN Stands for Public Switched Telephone Network. It is the infrastructure owned and operated by BT and other telecommunications companies.

Q, R, S, T, U

Router A device used to share an internet connection between multiple computers. Routers perform NAT functions, and some also include DHCP and basic firewalls.

Splitter This splits the ADSL signal and your normal telephone signals. One is needed for every telephone connected to an ADSL enabled telephone line.

Switch A device used on LANs to connect computers together. A switch usually has multiple RJ45 sockets, each of which will support the connection of one device (usually a computer). Standard connection speeds are 10/100Mbps.

TIA the Telecommunications Industry Association (TIA) is a non-profit organisation responsible for telecommunications standards.

V, W, X, Y, Z

VPN Stands for Virtual Private Network. This is a technology which allows secure private connections across public networks (usually the internet). It is used to allow remote offices or home-workers to connect to a corparate LAN.

WAN Stands for Wide Area Network. These consist of a number of LANs sometimes many miles apart, connected together via high speed data links.