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Home page General Glossary


Access network


Access network: the part of a network than runs into or close to homes and businesses, extending out of a local exchange.



Asymmetric Digital Subscriber Line: DSL is a technology that transforms an analogue telephone line into a high speed digital line. Incoming and outgoing data speeds are different with ADSL. See: Business Broadband.



Asynchronous Transfer Mode: an international CCITT standard for high speed, packet-switched networks that operate at digital transmission speeds above 1.544 Mbps.



Backhaul: the process of sending locally aggregated traffic gathered at a local level onto a backbone network.



Business Exchange Line: another term for Business Phone Lines.



Broadband comes from the words "broad bandwidth" and is used to describe a high-capacity, two-way link between an end user and access network. See: Business Broadband.

Cable modem


Cable modem: a high speed modem allowing users to connect to a service provider through their local cable network to have an 'always on' connection to the Internet. See: Business Broadband.



Class of Service: a term used to divide the source traffic from a user into a number of separate classes, each attracting its own quality of service indicators. 



Customer Premise Equipment: communications equipment located at a customer’s premises.



Carrier Pre-Select: a service that allow you to connect to our network and benefit from our competitive call rates, while retaining your existing numbers.



Domain Name Service/Server: an internet protocol for relating service names to URLs to an IP address and vice versa.



Denial of Service. An electronic attack whose purpose is to prohibit an opponent the use of a program or an entire system.



Digital Subscriber Line: technology that transforms an analogue telephone line into a high speed digital line.



The European standard for digital transmission, carrying data at 2 Mbps.



A method of connecting computers in a LAN (Local Area Network) to transfer data over a communication cable. Used in our Ethernet Extensions, National Ethernet and Ethernet VPN services.



File Transfer Protocol: A method for sending files between computers.



Internet Protocol: a standard method of sending information from one computer to another across the internet.

IP Address


Internet Protocol Address. A numeric address that is given to servers and users connected to the Internet.



Internet Protocol Private Branch eXchange: an Internet Protocol-enabled PBX which sends voice traffic over a data network instead of a traditional phone network. It provides features such as employee dial tones, extension dialling, transfer or conference calls.



A virtual private network (VPN) implementation based on the IPsec (Security Architecture for the IP Protocol, RFC2401) standard. See: IPSec VPN.



Internet Protocol Virtual Private Network: a way of using the internet to link up separate sites of an organisation. See: IPVPN with MPLS.



Integrated Services Digital Network: an international standard for sending voice, video, and data over digital or analogue telephone lines.



Interactive Voice Response: a system that permits the voice control of computer systems, often via a touch-tone telephone, allowing the user to interact with a database by voice.



Kilobits per second: a measure of data transmission.



Local Area Network: a high speed communications network covering a small geographical area, such as an office or group of offices.

Layer 1, 2, 3


Layer 1, 2, 3: Layer 1 is the most fundamental element of a network’s infrastructure. This basic hardware is often made available as ‘dark fibre’, which customers can overlay with their own services and manage for themselves. Layer 2 provides the means to send data over the network from site to site, and still offers the wholesale customer the chance to add their own value. Layer 3 is the so-called ‘network layer’, where data can be handled with greater sophistication and bundled into packets. Subsequent layers concern actual applications and services.

Leased Lines


A point-to-point connection between two sites, which is leased from the network operator. See: Leased Lines



Local Loop Unbundling: Traditionally, access networks based on copper connections were always the exclusive property of a national incumbent telco. But in an era of deregulation, incumbent telcos are compelled to make access to this copper available to other competitive service providers in the market. This process is now known as Local Loop Unbundling.



Metropolitan Area Network: a high speed communications network covering an area larger than a LAN and smaller than a WAN.



Megabits per second: a measure of data transmission.



Megabytes per second: a measure of data transmission. 1 megabyte = 8 megabits.



Multi-Protocol Label Switching: a labelling standard to manage traffic based on priority and service plans. It is multi-protocol because it works with (IP) Internet Protocol, (ATM) Asynchronous Transport Mode, and frame relay network protocols. See: IPVPN with MPLS.

Network density


A dense network offers connections to or near to a large proportion of potential users in a given region.



Private Branch eXchange: a private telephone network within an organisation allowing users to share external telephone lines instead of having a dedicated external line for every telephone.



Plesiochronous Digital Hierarchy: a multiplexed technology used for transmitting digital information over optical networks.



Point of Presence: a point of connection to a service provider's network. The more POPs offered by a provider, the more customers can access the service through a local call.



Plain Switched Telephone Network: a traditional wired telephone network.



Quality of Service: a term used to denote how different classes of information are handled in a network. For example, voice require a higher QoS than data. This usually includes parameters such as end-to-end delay, jitter and loss.  



A device or setup that finds the best route between any two networks, even if there are several networks to traverse. Remote sites can be connected using routers.



Symmetric Digital Subscriber Line. A high-speed internet connection that offers matching upload and download speeds, as in our Managed Internet Access service.



Synchronous Digital Hierarchy: a standard for transmitting digital information over optical networks. See: Leased Lines



Session Initiation Protocol: used to set up communications sessions on the Internet, such as telephony, presence, events notification and instant messaging.



Simple Mail Transfer Protocol is a protocol used to send and receive email.



SSL VPN (Secure Sockets Layer Virtual Private Network) is a type of VPN that runs on Secure Socket Layers technology. See: SSL VPN.



Virtual Private LAN Service. A way to provide Ethernet based multipoint to multipoint communication, used in our Ethernet VPN service.

Virtual LAN


Virtual Local Area Network: A logical rather than a physical LAN comprising workgroups drawn together for business reasons or for a particular project irrrespective of each member's actual location.  



Voice over Internet Protocol: a method of transmitting voice calls over the internet.



Virtual Private Network: a private network that uses the public telecoms infrastructure.



Wide Area Network: a high speed communications network covering a wide geographical area.



Wholesale Line Rental: a service that allow you to connect to our network. With Wholesale Line Rental, you can transfer the ownership of your existing lines to us.