Glossary of Broadband Internet Terms

This glossary is to compliment the document How to share a broadband internet connection.

10BaseT

An Ethernet specification that operates at 10Mbps over two pairs of twisted-pair category 3, 4, or 5 cabling. One pair is used to send data and the other is used to receive data. 10BaseT has a distance limit of about 100m. See also 100BaseT and Fast Ethernet.

100BaseT

The Fast Ethernet specification operating at 100Mbps using UTP wiring. See also 10BaseT and Ethernet.

Address Resolution Protocol (ARP)

ARP is the protocol that traces IP addresses to MAC addresses - see also Reverse Address Resolution Protocol (RAPP).

ADSL

see Asymmetric Digital Subscriber Line (ADSL)

ARP

see Address Resolution Protocol (ARP)

Asymmetric Digital Subscriber Line (ADSL)

ADSL is a technology for transmitting digital information at a high bandwidth on existing telephone lines. Unlike a regular dial-up telephone service, ADSL provides an "always on" connection. ADSL is asymmetric in that it uses most of the channel to transmit downstream to the user and only a small part to receive information from the user. ADSL simultaneously accommodates analogue (voice) information on the same line. See also Digital Subscriber Line (DSL).

BootP

see Bootstrap Protocol (BootP)

Bootstrap Protocol (BootP)

A protocol used to dynamically assign IP addresses and gateways to requesting clients

Broadband

A transmission technology that allows multiple signals to share one cable.

Crossover cable

A type of Ethernet cable that connects a switch to a switch, a host to a host, hub to hub or switch to hub. See also straight-through cable.

DHCP

see Dynamic Host Configuration Protocol (DHCP)

Digital Subscriber Line (DSL)

DSL is a technology for bringing high-bandwidth information to homes and small businesses over ordinary copper telephone lines. xDSL refers to different variations of DSL, including ADSL, HDSL, and RADSL. See also Asymmetric Digital Subscriber Line (ADSL).

DNS

see Domain Name System (DNS)

Domain Name System (DNS)

Used to resolve host names to IP addresses

DSL

see Digital Subscriber Line (DSL)

Dynamic Host Configuration Protocol (DHCP)

DHCP is a protocol that uses a server to dynamically configures a client when requested. DHCP is similar to BootP with the addition of address pools and lease times. See also Bootstrap Protocol (BootP).

Ethernet

A LAN specification created by the Xerox Corporation, and then improved by Xerox, Digital Equipment Corporation and Intel. Operates over cables at 10Mbps. See also Fast Ethernet, 10BaseT and 100BaseT

Fast Ethernet

Any Ethernet specification operating at a speed of 100Mbps (i.e. 10 times faster than 10BaseT). See also Ethernet, 10BaseT and 100BaseT.

Firewall

A barrier between any connected public network and private network that prevents unauthorised traffic passing through it.

Hub (network)

A device that is essentially a multiport repeater. When an electronic digital signal is received on a port, the signal is amplified and forwarded out on all segments except the segment from which the signal was received. See also switch.

Internet Protocol (IP)

A network layer protocol that is part of the TCP/IP stack and allows connectionless service.

IP

see Internet Protocol (IP)

IP Address

Often called an Internet Address, this is an address which uniquely identifies any device on the internet.

LAN

see Local Area Network (LAN)

Local Area Network (LAN)

Any network linking two or more computers and devices within a limited geographical area.

MAC address

a hardware address that every port or device needs in order to connect to a LAN segment.

Modem

modulator-demodulator - a device that converts digital signals to analogue and vice-versa so that digital information can be transmitted over analogue communication facilities, such as telephone lines.

NAT

see Network Address Translation (NAT)

NetBIOS

see Network Basic Input/Output System (NetBIOS)

Network Address Translation (NAT)

An algorithm that minimises the requirement for globally unique IP addresses. Typically used to enable hosts on a private network to connect to the internet without having unique IP addresses (or Internet-routable IP addresses).

Network Basic Input/Output System (NetBIOS)

The API employed by applications residing on an IBM LAN to ask for services, such as session termination or information transfer, from lower-level network processes.

Network Card

see Network Interface Card (NIC)

Network Interface Card (NIC)

An electronic circuit board placed in a computer that enables the computer to communicate with a LAN.

NIC

see Network Interface Card (NIC)

PAT

see Port Address Translation (PAT)

Plain Old Telephone Service (POTS)

this refers to the traditional analogue phone service commonly encountered.

POTS

see Plain Old Telephone Service (POTS)

Point-to-Point Protocol (PPP)

The protocol most commonly used for dial-up internet access.

Point-to-Point Protocol over Ethernet (PPP)

PPPoE is the protocol used by many ADSL Internet Service Providers to connect customer computers to a remote site (i.e. the ISP) through standard telephone equipment.

Port Address Translation (PAT)

allows a single IP address to represent multiple resources by altering the source TCP or UDP port number.

PPP

see Point-to-Point Protocol (PPP)

PPPoE

see Point-to-Point Protocol over Ethernet (PPPoE)

RARP

see Reverse Address Resolution Protocol (RARP)

Reverse Address Resolution Protocol (RARP)

RARP is the protocol that maps MAC addresses to IP addresses - see also Address Resolution Protocol (ARP)

Router

A device that decides on the best path to use for the transmission of network traffic. Also referred to as a Gateway.

Server

Hardware and software that provide network services to clients

Straight-through cable

Type of Ethernet cable that connects a host to a switch, a host to a hub, or router to a switch or hub. See also crossover cable

Switch (network)

A device that is similar to a hub but with additional intelligence. Digital signals received on a port are forwarded out only on the port required for the signal to reach it's destination. This reduces network collisions and improves network performance. See also hub.

TCP

see Transmission Control Protocol (TCP)

TCP/IP

see Transmission ControlProtocol /Internet Protocol (TCP/IP)

Transmission Control Protocol (TCP)

A connection-oriented protocol that provides reliable delivery of data.

Transmission Control Protocol/Internet Protocol (TCP/IP)

The suite of protocols underlying the Internet.

UDP

see User Datagram Protocol (UDP)

Unshielded Twisted Pair (UTP)

Copper wiring used in small-to-large networks to connect host devices to hubs and switches.

User Datagram Protocol (UDP)

A connectionless transport layer protocol in the TCP/IP protocol stack that simply allows datagrams to be exchanged without acknowledgements or delivery guarantees.

UTP

see Unshielded Twisted Pair (UTP)

WAN

see Wide Area Network (WAN)

Wide Area Network (WAN)

Is a designation used to connect LANs together.

Windows Internet Name Service (WINS)

Name resolution database for NetBIOS names to TCP/IP address.

WINS

see Windows Internet Name Service (WINS)