Telecommunications and IT is full of confusing terms and acronyms. To make life easier, we’ve created this useful glossary of the most often used terms.

Asymmetric Digital Subscriber Line (ADSL)

ADSL is a method for moving data over regular phone lines. An ADSL circuit is much faster than a regular phone connection, and the wires coming into the premises are the same (copper) wires used for regular phone service. An ADSL circuit must be configured to connect two specific locations, similar to a leased line.

Asynchronous Transfer Mode (ATM)

ATM is a dedicated connection switching technology that organises digital data into 53-byte cell units and transmits them over a physical medium using digital signal technology. The pre-specified bit rates are either 155.520 Mbps or 622.080 Mbps (Megabits per second), though speeds on ATM networks can reach 10 Gbps (Gigabits per second).


Each Internet Service Provider has major high speed lines or a series of connections that form their network infrastructure.These connections could be viewed as motorways for internet traffic with junctions where traffic can join the rest of the network. The size (bandwidth) of connections varies depending on the size of the provider.


Describes how much data you can send through an internet connection and is usually measured in bits-per-second. As a rule, increased bandwidth equals faster internet connections.


In telecommunications, broadband is wide bandwidth data transmission with an ability to simultaneously transport multiple signals and traffic types. The medium can be coaxial cable, optical fibre, twisted pair, DSL local telephone networks or wireless broadband (wireless broadband includes Mobile broadband).


Most often used to refer to having a server that belongs to one person or group physically located on an internet connected network. We offer co-location web server hosting providing a secure high speed internet connection for mission critical hosting applications.

Customer Premises Equipment (CPE)

Customer Premises Equipment refers to hardware located at the premises of a customer such as broadband internet routers, VoIP base stations, telephone handsets or other customised hardware.

Data Encryption Standard (DES)

Data Encryption Standard is a widely used method of data encryption that uses a 40-bit and 56-bit key to encrypt and decrypt data. DES and Triple-DES are used as encryption algorithms by S/MIME.

Domain Name Server(DNS)

DNS is used to map names to IP addresses and vice versa. Domain Name Servers maintain central lists of domain name/IP addresses and map the domain names in your internet requests to other servers on the internet until the specified web site is found.

Dynamic IP

This term is used to describe how an IP address is automatically assigned to computers as and when needed. Unlike static IP addresses, the IP address is temporary e.g. when you connect to your ISP using a dial up connection, your PC or router will be automatically assigned an IP address whilst you are online.


Essentially all broadband products be they ADSL, ADSL2+ or FTTC, connect to the broadband part of the network. This means that they don’t carry a guaranteed level of service and are all contended to some degree, which in a nutshell means that you will neither get a constant speed or connection. If you have a faulty connection Openreach (who deal all faults regardless of provider) can take up to 40 working hours to repair a connection, as yourself the question could you manage without connectivity for a whole week?

Ethernet First Mile (EFM)

This is a copper wires based service that delivers connectivity via the Ethernet part of the network. Available in either dual or quad configurations. Speeds are dependent on distance from the exchange like broadband, but are uncontended and are supported by a comprehensive service level agreement, guaranteeing both speed and connectivity.


A firewall is a combination of hardware and software that secures access to and from the LAN. There are three main types of firewall architecture - Stateful Inspection, Proxy based and Packet Filtering. The former provides the highest level of access control. Firewalls can also be used to secure internal network resources from internal network users too.

Gemini Generic Ethernet Access (GEA)

This service takes the FTTC service from being positioned within the ADSL arena into the Ethernet arena, with other more expensive products like EFM and MIA, which is supported by a comprehensive service level agreement, guaranteeing both speed and connectivity.


A Geo-fix is a number with a 01 or 02 dialling code relating to a specific geographic area. Calling a geo-fix number carries the same call charge as any standard geographic telephone number and they can be used to provide a local presence. Geo-fix numbers can be offered with the same inbound call handling features as an NTS (Number Translation Service) number.There are charges to the called party based on the terminating number used: non-geographic number (NGN), geographic, mobile, international etc.

Gigabit (Gb)

In data communications, a gigabit is one billion bits. It is commonly used for measuring the amount of data that is transferred in a second between two telecommunication points.

Internet Protocol (IP) Address

Also sometimes called a dotted quad. It is a unique number consisting of 4 parts separated by dots e.g. Every machine that is on the internet has a unique IP number - if a machine does not have an IP number, 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 Security (IPSec)

A standard for security at the network or packet processing layer of network communication. IPSec essentially encrypts data to create secure data transmissions across private and public networks such as the internet and allows companies to implement VPNs (Virtual Private Networks) across the internet as a cost effective alternative to dedicated connections.

Integrated Services Digital Network (ISDN)

ISDN is a type of digital phone/data and internet service that preceded ADSL and has for the most part been superseded by it.

Local Area Network (LAN)

These are networks of computers that are local to the immediate area, usually the same building or floor of a building. LANs allow files, information and resources to be shared or stored centrally for all users that have a connection to it.

Leased Line

Leased line refers to a dedicated phone line that is rented for exclusive 24 hour, 7 days a week use from one location to another location. The highest speed data connections require a leased line.

Managed Internet Access (MIA)

This is a fibre based service that delivers the best connectivity via the Ethernet part of the network. MIA offers a flexible option with uncontended speeds from 10Mbps-1Gbps and are supported by a comprehensive service level agreement, guaranteeing both speed and connectivity.

Megabit (Mb)

A measure, representing 1 million bits, generally used to express the speed per second of telecommunications services and equipment. A bit is the smallest unit used to express digital information.

Multi-Protocol Label Switching (MPLS)

MPLS is a way to speed up the flow of traffic on a network by making better use of available network paths. It designates the proper path for each function so that the opportunities for bottlenecks within the network are minimized.

Network Address Translation (NAT)

NAT is the translation of an IP address used within one network to a different IP address known within another network. Typically a company maps its local inside network addresses to one or more global outside IP addresses and unmaps the global IP addresses on incoming packets back into local IP addresses. This helps ensure network security since each outgoing or incoming request must go through a translation process that also provides the opportunity to qualify or authenticate the request or match it to a previous request. NAT also conserves the number of global IP addresses that a company needs by letting a company use a single IP address to communicate with the world. NAT is also a feature of most routers and firewalls.

Network Operating Centre (NOC)

Network operating centre is a central location for monitoring and maintaining a network.

Number Translation Services (NTS)

The routing by the TalkTalk Business Intelligent Network of inbound calls made to a non geographic number (NGN) on to a terminating number.

Packet Internet Groper (PING)

This is a command that can be used to check if communication can be established between two devices. The information that is returned includes how long it takes for the data to make the journey, how many hops across the internet (or router path) it took and how much of the traffic gets through.

Point of Presence (POP)

Point of presence usually means a city or location where an Internet Service Provider provides local access to connect to the internet using dial up phone lines and leased lines. We currently have almost 50 POPs in the UK alone.

Public Switched Telephone Network (PSTN)

This is the world's collection of interconnected voice oriented public telephone networks, both commercial and government owned. It's also referred to as the Plain Old Telephone Service (POTS).

Remote Authentication Dial-In User Service (RADIUS)

Remote authentication dial-in user service is a client/server protocol and software that enables remote access servers (RAS), to communicate with a central server to authenticate dial-in users and authorise their access to the network. RADIUS allows a company to maintain user profiles in a database that all remote servers can share and allows a company to set up a remote access policy that can be applied at a single administered network point.


A router is a piece of hardware that essentially connects two or more networks together. Routers forward packets of data between networks based on network layer information, or in other words, it looks at the destination addresses of the packets passing through it and decides which route to send them on.


No phone line, just a small satellite dish pointed at the sky.

For some customers standard broadband is either not available, to slow or to unreliable that Satellite broadband is the only connectivity option. Satellite broadband can help with download speeds of up to 20Mbps and an upstream of up to 10Mbps. A package can be specifically designed for you depending on your monthly downloads as with satellite connectivity the download limit is strictly enforced and could expensive option for the heavy downloader.

Software as a Service (SaaS)

SaaS is typically accessed by users using a thin client via a web browser. SaaS has become a common delivery model for many business applications, including office & messaging software, payroll processing software, DBMS software, management software, CAD software, development software

Session Initiation Protocol (SIP)

SIP is a signalling protocol used for establishing sessions in an IP network. A session could be a simple two-way telephone call or it could be a collaborative multi-media conference session. The ability to establish these sessions means that a host of innovative services become possible, such as voice enriched e-commerce, web page click-to-dial, Instant Messaging with buddy lists, and IP Centrex services.

Symmetric Digital Subscriber Line (SDSL)

This is a DSL service that transmits and receives data at the same speed in both directions.

Secure Sockets Layer (SSL)

Secure sockets layer is a protocol designed by Netscape Communications to enable encrypted, authenticated communications across the internet. SSL is used mostly (but not exclusively) in communications between web browsers and web servers. URLs that begin with “https” indicate that an SSL connection will be used. SSL provides 3 important things: privacy, authentication and message integrity.

Static IP

Static IP is the term used to describe a PC or network device that has a permanent IP address as opposed to a dynamic IP address.

Transmission Control Protocol/Internet Protocol (TCP/IP)

Common names for the suite of protocols developed to support and unify the construction of worldwide internetworks such as the internet. TCP and IP are the best known protocols in the suite.

Triple DES

Triple DES is an enhanced version of DES that allows for more security than DES alone, triple DES uses three keys and encrypts three times – hence ‘triple’.

Virtual Private Network (VPN)

This usually refers to a network in which some of the parts are connected using the public internet, but the data sent across the internet is encrypted, so the entire network is "virtually" private.

Wide Area Network (WAN)

This is a geographically dispersed network.

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