Telecoms Jargon Buster

Our Telecoms Jargon Buster page is your ultimate guide to demystifying the complex terminology of the telecommunications industry. From acronyms like VoIP and PSTN to terms like bandwidth and latency, navigating the world of telecoms can often feel like deciphering a foreign language. Our comprehensive jargon buster is here to decode the technical language and help you understand the ins and outs of telecommunications technology.

Whether you’re a small business owner looking to upgrade your phone system or an IT professional managing a complex network infrastructure, our user-friendly glossary provides clear definitions and explanations to empower you with the knowledge you need to make informed decisions and communicate effectively in the world of telecoms.


Fourth generation (4G) technology allows ultra-high-speed data transfer. In optimal conditions, 4G can enable data to be transmitted 10 times faster than via 3G.

Fifth generation (5G) is the latest technology in mobile data and is set to bring even faster data transmission up to 100 times faster than 4G meaning streaming and downloads will take a fraction of the time. 5G has already arrived in some parts of the world and is set to begin rolling out in the UK from late 2019.


Access Control
The action of permitting or denying admittance, e.g. a facial recognition camera or ID card reader terminal placed at the entrance of a building for security reasons. See also Flow Management and Density Control.

Analogue Device
An analogue device is anything that can be plugged into an ordinary analogue line, for example a telephone, fax machine, modem or franking machine.

Analogue Line
An analogue line is a single copper cable run into a building by the line provider. Analogue lines were used for both voice and data before ADSL was available but they are now typically used for analogue devices as well as broadband connections, alarms and lifts. These will soon become obsolete due to the PSTN switch off.

Android OS is an open-source operating system developed by Google for mobile devices, such as smartphones and tablets. Known for its flexibility, customization, and extensive app ecosystem, Android powers a majority of the world’s mobile devices and brands including Samsung, Google, Nokia, Motorola and more. It provides a user-friendly interface and supports a wide range of applications, making it a popular choice for device manufacturers and users alike.

Annex M
Annex M is a feature available on ADSL connections which provides an increase in upload speed in exchange for some of the download bandwidth.

This is software that attempts to protect your computer from malicious internet-transferred malware (malicious software normally designed to be intrusive or damaging to your computer such as viruses, Trojan horses and worms).

Application (App)
Applications are software programmes designed to run on mobile devices such as mobiles and tablets, however some apps are developed for desktop use.

Artificial Intelligence (AI)
Artificial Intelligence (AI) is computer algorithms capable of performing human actions such as recognition, perception and decision-making.

Asymmetric Digital Subscriber Line (ADSL)
Asymmetric Digital Subscriber Line (ADSL), more commonly known as broadband, is a high-speed digital line enabling internet access. ADSL has good download speeds (typically up to 24MB/s) but can be slower for uploading (up to 1.5Mb/s).

Auto Attendant (AA)
An Auto Attendant, or Automated Attendant (AA), is a voice menu system that greets callers and offers a number of choices as to where their call can be directed. Callers can select an option using their phone keys in order to route their own call.

Auto Dialler
An auto dialler, or automatic dialler, is a device or software that automatically dials from a list or customer database, frequently used in call centres. When the call is answered, the auto dialler can play a pre-recorded message or connect the call to an available agent.

Automated Backup
Delivers the most basic form of storage availability — recoverable data.

Automatic Call Distribution (ACD)
Automatic Call Distribution (ACD) answers and routes incoming calls to groups or individuals within an organisation. Commonly used in call centres, the ACD system disperses calls to available agents based on a set of instructions (e.g. longest idle, next available agent, specific skills etc.) enabling the call to be answered and dealt with as quickly as possible.


The server side of a client/server system. A ‘front-end’ application is one that application users interact with directly. A ‘back-end’ application or program serves indirectly in support of the front-end services.

Back-up Server
A software or hardware system that copies or “shadows” the contents of a server, providing redundancy.

Bandwidth is what dictates the speed at which data can be transmitted within a circuit; the bigger the bandwidth, the faster the data transmission.

Basic Rate Interface (BRI)
Basic Rate Interface (BRI) is an Integrated Services Digital Network (ISDN) primarily used for homes or small businesses. A BRI comprises two data channels (also known as bearer channels/B-channels) and one control channel (also known as a delta channel/D-channel) and can facilitate two independent calls.

Bearer Channels (B-channels)
A bearer channel (B-channel) carries main data on the Integrated Services Digital Network (ISDN).

Bluetooth is a wireless technology enabling data transmission from one device to another in close proximity.

A bolt-on is a mobile service that can be added to an existing tariff to increase the inclusive allowance, e.g. additional text messages, minutes or data.

Bonded Solution
A bonded solution combines multiple broadband connections (ADSL/fibre/ethernet) to provide a greater bandwidth than would otherwise be available.

Bring Your Own Device (BYOD)
Bring Your Own Device (BYOD) refers to employees who bring their own computing devices to use in the workplace and to connect to the corporate network. BYOD security is often addressed by having IT provide detailed security requirements for each type of personal device used in the workplace. For example, configuring passwords, prohibited access, or data encryption.

BT (British Telecom)
The UK’s largest provider of fixed-line, broadband and mobile services. They also provide subscription television and IT Services.

A bundle is a combination of inclusive services within a fixed cost. This could be text messages, minutes and data for a mobile device or a selection of cloud features for IP telephony (e.g. Voicemail, Busy Lamp Field and Call Queueing).

Busy Lamp Field (BLF)
A Busy Lamp Field (BLF) is when lights on a handset indicate if an extension connected to the same telephone system is engaged.

This is a measurement of how much information is in a message.
Megabyte = 1,000,000 bytes
Gigabyte = 1,000,000,000 bytes
Terabyte = 1,000,000,000,000 bytes
Petabyte = 1,000,000,000,000,000 bytes
Exabyte = 1,000,000,000,000,000,000 bytes
Zettabyte = 1,000,000,000,000,000,000,000 bytes
Yottabyte = 1,000,000,000,000,000,000,000,000 bytes


Call Barring
Call barring prevents users from dialling selected destinations such as international or premium rate numbers. This can be applied at a system or network level and can be reversed on request.

Call Blocking
Call blocking is the function of automatically rejecting incoming calls from certain numbers.

Call Deflection
Call deflection is a feature that automatically redirects and incoming call to an alternative destination (e.g. a mailbox or another extension) when the called endpoint is engaged.

Call Detail Record (CDR)
A Call Detail Record (CDR) is a data file containing information about recent usage on the phonelines (e.g. origin, endpoint, duration or cost) made via and endpoint.

Call Forwarding
Call forwarding is a feature that diverts incoming calls to another endpoint (e.g. another extension, a mailbox or a mobile number). The divert can be applied to forward all calls or programmed to only forward calls when busy or if the call goes unanswered.

Call Logging
Call logging is the function of capturing statistics about both incoming and outgoing call traffic which can then be used for analysis and reporting with call management software. Call data can be viewed in its entirety or filtered by number or extension.

Call Management
Call management software facilitates analysis and reporting on the call statistics captured by a call logger.

Call Park
A call park is a feature whereby a user can place a call on hold which can be retrieved from any extension.

Call Queueing
Call queueing is where the calls are placed in a virtual queue in the order in which they are received before they can be answered by an available call handler. Some call queueing software enables position announcements, music on hold, marketing messages and the functionality to request a ring-back.

Call Recording
Call recording is the process of capturing both inbound and outbound conversations as digital audio files. Recorded calls are stored and may be searched with multiple criteria.

Calling Line Identity (CLI)
A Calling Line Identity (CLI) is the telephone number associated with a line. This can be presented or withheld when a call is made and a user can choose to present an alternative CLI.

Calling Line Identity Presentation (CLIP)
Calling Line Identity Presentation (CLIP) is when the telephone number is provided to the call recipient.

Calling Line Identity Restriction (CLIR)
Calling Line Identity Restriction (CLIR) is when the telephone number is withheld from the call recipient.

A carrier is a telecommunications service provider that owns their own network, e.g. BT or Gamma.

Carrier Pre-Selection (CPS)
Carrier Pre-Selection (CPS) is the process of routing calls via a service provider’s chosen network.

Category 5 or CAT5 (or CAT5e) is the specification for the transmission performance of an ethernet data cable but is frequently used to describe structured cabling routing voice and data circuits to wall sockets within a building. CAT5/5e transmission can be up to 100MHz.

Category 6 or CAT6 is an upgrade to CAT5/5e cable enabling performance of up to 250MHz compared to 100MHz with CAT5/5e. CAT6 is backwards compatible with CAT5/5e ethernet cables.

Category 7 or CAT7 is used for Gigabit Ethernet cabling infrastructure offering transmission performance up to 600MHz.

Central Control Unit (CCU)
The Central Control Unit (CCU) is the box or cabinet that houses the hardware controlling the telephone system.

Centrex (short for Central Exchange) is a hosted telephony solution providing the functionality of a PBX without the costs and logistics associated with a physical on-premise system.

Class of Service
The ability to give a data packet a series of set properties/restrictions/access levels during a telephone call. E.g. A user can be given a COS value of 1 that permits international dialling while the value of 2 disables this ability.

Closed Circuit Television (CCTV)
Closed Circuit Television (CCTV) is the security and surveillance devices that can aide with access control and the broader protection of premises.

Cloud can relate to any kind of infrastructure, platform or applications that are hosted on a server not located at the premises using it, accessed via the internet. E.g. cloud communications enable the functionality of a telephone system with no requirement for an on-site PBX.

A codec is a device or piece of computer software for coding or decoding digital data streams or signals.

Communications Provider
An organisation that provides telephony services, e.g. Daisy Communications.

Communications Service Provider (CSP)
A Communications Service Provider (CSP) handles the electronic transmission of information.

Computer Telephony Integration (CTI)
Computer Telephony Integration (CTI) is a software that brings together your customer database and your telephones, enabling features like click-to-dial, screen popping and text messaging services.

Conferencing occurs when more than two telephone users join into a single call. Users can dial in to a conferencing destination or one participant can dial another and connect them into the call.

Connected Line Presentation (COLP)
Connected Line Presentation (COLP) is a feature whereby the caller is presented with the CLI of the user they have connected to, where this is not the number originally dialled. This is a chargeable service from the network provider and requires compatible equipment.

Contact Centre
A contact centre is a fully integrated customer-centric communication hub. Agents handle calls with merged with other media sources such as CRM applications.

Contention is where two or more nodes compete to transmit data at the same time. The contention protocol defines the rate of service in this situation. A network with zero-contention means there is no competition for transmission and the entire bandwidth is solely available for use by the network user.

Contention Ratio
This is the number of devices that may be sharing the same connection to the internet from the Broadband provider. Most standard ADSL Broadband packages have a contention ratio of 50:1. Meaning that up to 49 other users may be sharing the connection. Broadband providers can offer varied contention ratios from 20:1 to 1:1.

Convergence is the interlinking of multiple voice and data technologies and solutions into a single network.

Customer Premise Equipment (CPE)
Customer Premise Equipment (CPE) is the hardware owned and housed by the customer.

Customer Relationship Management (CRM)
A Customer Relationship Management (CRM) system is a piece of software that houses all information relating to customers, enabling an employee to have a single yet comprehensive view of a customer.


D-Side (short for Distribution Side) is the segment of cabling between the Primary Connection Point (PCP) and the distribution point (DP). The D-Side is then patched to the E-Side (Exchange Side).

Data in the context of telecoms is a term broadly used to mean internet access.

Data Allowance
A data allowance is what is included within a mobile tariff. A user may be able to exceed their inclusive data but this is usually chargeable. A data cap can be applied to prevent a user surpassing their allowance.

Data Cap
Many broadband service providers have a usage limit on the maximum amount of data you can download for a cheaper price. This is called a ‘cap’ Often there can be a cap on how much you are allowed to download on a certain contract – if you exceed this cap, you may have to pay an excess charge.

Data Centre
A facility used to store and manage data and associated components. Generally includes backup power supplies, redundant data communication connections, environmental controls, maintenance and security.

Dedicated Line (Internet)
A dedicated line, also known as a leased line or Ethernet circuit, is an ‘All IP’ connectivity solution designed for businesses with high data demands and critical operations. Unlike shared connections, a dedicated line provides exclusive, symmetrical bandwidth for enhanced performance and reliability. With dedicated lines, businesses can enjoy consistent speeds, low latency, and secure connections, enabling them to support bandwidth-intensive applications, real-time collaboration, and seamless cloud access. By investing in a dedicated line, organisations can establish a resilient network infrastructure that offers scalable and high-performance connectivity to meet their ever-changing business requirements.

Delta Channels (D-channels)
A delta channel (D-channel) carries control and signalling information on the Integrated Services Digital Network (ISDN).

Denial of Service
Commonly referred to a “DOS Attack” where a malicious third party intends to temporarily or permanently disrupt the services on an endpoint.

Dense Wavelength Division Multiplexing (DWDM)
Dense Wavelength Division Multiplexing (DWDM) is the technology used to combine multiple fibre networks to create a broader bandwidth for the existing network.

Density Control
Density Control is when the number of individuals in a designated area must be measured or managed. See also Flow Management and Access Control.

Digital Access Signalling System (DASS)
Digital Access Signalling System (DASS) was BT’s original protocol for providing signalling to ISDN30. DASS is still supported but no longer available for new provides as ISDN30 was superseded by ISDN30e with ETSI or Q931 signalling which is now standard throughout Europe.

Digital Enhanced Cordless Telephony (DECT)
Digital Enhanced Cordless Telephony (DECT) is the technology for providing better clarity and smaller phones for cordless handsets (frequently called DECT phones). Mobile Devices are not included in this term.

Digital Private Network Signalling System (DPNSS)
A Digital Private Network Signalling System (DPNSS) supports connections between telecoms equipment from multiple vendors. See also Q Signalling (QSIG).

Digital Signal Processing
A piece of technology which can differentiate between the voice of an individual and background noise to improve the quality of sound. Premier Choice use this term to talk about a “DSP Card” which is a component used in most Panasonic PBX Solutions.

Digital Subscriber Line (DSL)
A Digital Subscriber Line (DSL) is used to add broadband with equal bandwidth in both directions to a phone line. The most common DSL line is an ADSL line.

Digital Subscriber Line Access Multiplexer (DSLAM)
A Digital Subscriber Line Access Multiplexer (DSLAM) is a network distribution device that receives signals from multiple Digital Subscriber Lines (DSL) and connects them into a single high-speed digital communication channel.

Digital Transformation
Digital Transformation is a buzz-word for the growth companies undergo as a result of introducing and combining innovative technologies.

Direct Dial Inward (DDI)
A Direct Dial Inward (DDI) is an inbound or outbound number assigned to a specific handset and associated to the main CLI. This feature is not available on analogue lines.

Direct Exchange Line (DEL)
A Direct Exchange Line (DEL) is term used for a single analogue line.

Direct Internet Access (DIA)
Any standalone internet circuit not part of a wider joint network.

Direct Station Selector (DSS)
A Direct Station Selector (DSS) is a unit that sits alongside a telephone enabling the handset to be used a reception/switchboard console. The unit provides programmable buttons enabling the operator to quickly dial and see the status of user extensions.

Disaster Recovery (DR)
Disaster Recovery (DR) is the continuity plan put in place for when there is a power failure or fault with the telecoms solution.

Distribution Point
The final point within a network where the cable or fibre terminates, typically the street (telegraph pole), cabinet or premises.

This is the address of a particular website, for example is a domain name.

Domain Name System (DNS)
A centralised system which categorises multiple network locations with a label (e.g. a domain). To save entering the full network address (possibly in numeric form) a simple domain label can attributed (e.g.

Receiving information on to your computer from another source – e.g. the internet.

The total time a system is out of service.

Dual-Tone Multi-Frequency
A signalling protocol using the voice frequency band over a telephone line which allows numbers to be selected on a handset/mobile dial pad to initiate a further call route. Most telephone systems use this protocol to control their “Options” menu.

Ducts are the pipes underground holding copper and fibre lines.

Dynamic Routing
A method of Wide Area Network transmission that uses a router to select the most appropriate path for each section of data packet transmission along a network.


E-Side (short for Exchange Side) is the segment of cabling between the Primary Connection Point (PCP – usually a street cabinet) and the origin (exchange).

Early Life Fault (ELF)
An Early Life Fault (ELF) is when a new product is found to be faulty shortly after purchase, without misuse or damage caused by the user.

This is the process of translating data into a secret code for security and protection purposes.

A Ethernet line, also known as a leased line, is an ‘All IP’ connectivity solution designed for businesses with high data demands and critical operations. Unlike shared connections, a dedicated line provides exclusive, symmetrical bandwidth for enhanced performance and reliability. With dedicated lines, businesses can enjoy consistent speeds, low latency, and secure connections, enabling them to support bandwidth-intensive applications, real-time collaboration, and seamless cloud access. By investing in a dedicated line, organisations can establish a resilient network infrastructure that offers scalable and high-performance connectivity to meet their ever-changing business requirements.

Ethernet First Mile (EFM)
Ethernet First Mile (EFM) is a lower cost leased line solution alternative providing symmetrical upload and download bandwidth with zero-contention. EFM uses the copper network to deliver an Ethernet service to sites where Fibre to the Cabinet (FTTC) is not available. Speeds can be up to 20Mb/s.

Excess Construction Charges (ECCs)
Excess Construction Charges (ECCs) are incurred when the cost of providing services or dealing with situations is more than the standard charge, e.g. implementing copper or fibre where there previously wasn’t any.


Facial Recognition
Artificial intelligence (AI) within a camera device that can detect and identify a human face when an individual or individuals are in range of the terminal.

Fibre (short for Fibre-Optic) is a method of transmitting telephone signals and internet connectivity through an optical fibre. Fibre is frequently more cost effective than copper and does not suffer electromagnetic interference.

Fibre To The Cabinet (FTTC)
Fibre To The Cabinet (FTTC) is the term for broadband network architecture that brings fibre connectivity from the telephone exchange to the street cabinets. From here, it is connected to the premises with a further copper sub-loop. Bandwidth is determined by the distance from the cabinet the closer the destination point is to the cabinet, the faster the download and upload speeds will be.

Fibre To The Home (FTTH)
Fibre To The Home (FTTH) is the residential equivalent of Fibre To The Premises (FTTP).

Fibre To The Premises (FTTP)
Fibre To The Premises (FTTP), provides end-to-end fibre from the exchange directly to the destination site (without any copper lengths) resulting in faster speeds than Fibre To The Cabinet (FTTC).

Fiber optics is a high-bandwidth transmission technology that uses light to carry digital information. One fiber telephone cable carries hundreds of thousands of voice circuits. These cables, or light guides, replace conventional coaxial cables and wire pairs. Fiber transmission facilities occupy far less physical volume for an equivalent transmission capacity, which is a major advantage in crowded ducts. Optical fiber is also immune to electrical interference. Fibre-optic cable will one day replace the older copper cable that has been used on telephone lines for years.

Filter (Microfilters/Splitters)
This is a device that you plug into your phone socket in order to split voice (telephone) and data (internet) signals when using an ADSL internet connection. It is important to add a filter to all the telephone sockets that share the same line as the broadband that also have a telephone attached to them. If using the telephone for an incoming call or if a user is making a call through a socket that doesn’t have a filter then the connection can be interrupted.

A Firewall is a component within a network or computer system designed to identify and prevent any unauthorised access into a network from an external source.

Fixed Line
A fixed line is an analogue or digital connection provided by a cable enabling voice and/or data services.

Flow Management
Flow Management is the counting in or out of individuals through a designated gateway. See also Density Control and Access Control.


A gateway is a node on your network that acts like an interface to other networks. Typically this is the machine that the desktops and workstations connect through to access the internet. Usually a gateway is associated with a router.

General Packet Radio System (GPRS)
General Packet Radio System (GPRS) is the data service used by mobile devices when 3G/4G/5G is not available.

Generic Ethernet Access
Generic Ethernet Access is a type of leased line similar to Fibre To The Cabinet (FTTC) however it focuses the traffic over the ethernet network as opposed to the broadband.

Gigabyte (GB)
A Gigabyte (GB) is a unit of storage capacity. There are 1000 megabytes in one GB.

Global Positioning System (GPS)
Global Positioning System (GPS) is the technology used to locate the position of a mobile device on earth by receiving signals from orbiting satellites frequently used for mapping/navigation software.

Global System for Mobile Communications (GSM)
The Global System for Mobile communications (GSM) is the internationally used standard platform for mobile phones.

Group Ringing
Group ringing is when multiple extensions ring as the result of a single number being dialled. This could be programmed in a group ring set-up where all extensions ring simultaneously or as a hunt group.


Hard Drive
This is a piece of hardware used to store electronic information in a user’s computer.

Hosted telephony is a term used for cloud services that utilise the Voice over Internet Protocol (VoIP). The user may have handsets in their premises but the telephone system is off-site, in a data centre for example, and the features are accessed via subscription user licences. See also Cloud and Centrex.

Hot Spot
A hot spot is a location enabling users to obtain internet access wirelessly.

A hardware device that is used to network multiple computers together. It is a central connection for all the computers in a network. Information sent to the hub can flow to any other computer on the network. If you need to connect more than two computers together, a hub will allow you to do so.

Hunt Group
A hunt group is a rule applied to a telephone system that determines the order in which available extensions ring. This may be in a programmed order, first available or longest idle, for example.

Hybrid Cloud Computing
A mixture of both public and private cloud service options.


Integrated Services Digital Network (ISDN)
Integrated Services Digital Network (ISDN) is a circuit used for digital transmissions of voice, data and other network services. They are utilised over the Public Switched Telephone Network (PSTN). The common circuits are ISDN2 and ISDN30. In 2015, BT announced that they would be phasing out ISDN solutions and switching the network off entirely. This means existing ISDN capacity is being ceased and new orders will be not be accepted. Come 2025, the whole ISDN copper network and all associated solutions will no longer be supported.

Intelligent Cloud Queueing (ICQ)
Intelligent Cloud Queuing (ICQ) is a call queueing software that automatically answers the call and then holds callers in order until a handler is available to answer. Features can include callers hearing their position in the queue or informative messages as well as the facility to request a call-back once they are at the front of the line.

Interactive Voice Response (IVR)
Interactive Voice Response (IVR) is the ability for a computer or digital setup to interact with individuals e.g. inbound callers may transition through a telephone system to meet an appropriate destination. This may be a mix of voice and Dual-Tone Multi-Frequency (DTMF) inputs.

International Mobile Equipment Identity (IMEI)
International Mobile Equipment Identity (IMEI) is a unique identity number assigned to a GSM device that can be recognised and blocked by the network to which it is connected. It is useful for fraud prevention and to bar access using a stolen phone.

Internet of Things (IoT)
Internet of Things (IOT): refers to the billions of devices worldwide that are connected to the internet to receive and transmit data. IOT SIM cards can be supplied for GSM (Global System for Mobile communications – the internationally used standard platform for mobile phones) units if required for lift/alarm lines and other analogue services.

Internet Protocol (IP)
The Internet Protocol (IP) is the governing rules around the transmission of data via the internet or a network.

Internet Service Provider (ISP)
An Internet Service Provider (ISP) is a supplier enabling internet connectivity.

IP Address
An IP address is a unique set of numbers that identify each device accessing the internet or a network.


Kilobyte (KB)
A Kilobyte (KB) is a measurement of data. Approximately one thousand bytes.


A landline is the telephone that is traditionally brought to your home over copper, or fibre optic cable.

The time it takes for a packet of data to travel from one destination to the next. High latency tends to have more impact than bandwidth on the end-user experience in interactive applications, such as web browsing. Low latency is required for many next-generation IP applications, such as VoIP, video telephony and PTT.

Leased Line
A leased line, also known as a dedicated line or Ethernet circuit, is an ‘All IP’ connectivity solution designed for businesses with high data demands and critical operations. Unlike shared connections, a dedicated line provides exclusive, symmetrical bandwidth for enhanced performance and reliability. With dedicated lines, businesses can enjoy consistent speeds, low latency, and secure connections, enabling them to support bandwidth-intensive applications, real-time collaboration, and seamless cloud access. By investing in a dedicated line, organisations can establish a resilient network infrastructure that offers scalable and high-performance connectivity to meet their ever-changing business requirements.

Letter Of Authority (LOA)
A Letter Of Authority (LOA) is an OFCOM approved document completed by a client giving authorisation for an organisation (e.g. Premier Choice) to take ownership/control of telephone numbers currently operating with another service provider.

Local Area Network (LAN)
A Local Area Network (LAN) is typically confined to a residence or office building and shares a common communications link which is not internet facing.

Local Loop Unbundling (LLU)
Local Loop Unbundling (LLU) is the process of allowing numerous service operators to link connections from a telephone exchange to a client’s premises.

Long Term Evolution (LTE)
Long Term Evolution (LTE) is standard for wireless broadband communications for mobiles and data devices.


Media Relay Gateway (MRG)
A Media Relay Gateway (MRG) is a component within a network that handles and converts media to make it compatible between multiple devices. An example of an MRG Device (Endpoint) in the Premier Choice Network is a remote telephone registered to a central Panasonic phone system in a different network location.

Megabyte (MB)
A Megabyte (MB) is a unit of measurement. Approximately 1,000,000 bytes.

Mobile Broadband
Broadband for your laptop or tablet. All you need is a USB connection and you can get broadband while “on the go” or “mobile”. This uses 3G/4G technology or the newer, faster 5G.

Multi-Protocol Label Switching (MPLS)
Multi-Protocol Label Switching (MPLS) is a routing technique aimed at speeding up and shaping traffic flows across a network. This technique is used within our own Private Wide Area Network (PWAN).

Music On Hold (MOH)
Music On Hold (MOH) is the audio that plays when a live call is paused by an end user.


This is when two or more components are connected allowing resources to be shared between them.

Network Termination (NT)
Network Termination (NT) is the connection of an end user’s Network Termination Equipment (NTE) to a carrier’s line that comes into the premises at the Network Termination Point (NTP).

Network Video Recorder (NVR)
A Network Video Recorder (NVR) is a computer device that holds software capable of recording video in a digital format to a storage drive.


OFCOM (Office of Communications)
OFCOM are the regulatory body approved by the UK Government set with the task of overseeing all matters within television/radio and telecoms, that ensures fair competition and protects the public for harmful or offensive material.

Open Systems Interconnection (OSI)
Open Systems Interconnection (OSI) is a model that standardises the communication functions of a telephone or computing system. There are 7 key layers in the model ranging from the physical layer through to the application layer.

Openreach (OR)
Openreach (OR) are the department of BT which maintains the telephone cabling, cabinets and exchanges within the UK that connect nearly all homes and businesses.


Packet Switching
A technique in which a message is broken into smaller units called packets, which may be individually addressed and routed through the network, possibly using several different routes. The receiving-end node ascertains that all packets are received and in the proper sequence before forwarding the complete message to the addressee.

Plain Old Telephone Service (POTS)
Plain Old Telephone System (POTS) is the predecessor term to Public Switched Telephone Network (PSTN). It is the collection of analogue phone lines whose main purpose is to transmit voice calls.

Postal, Telegraph and Telephone service (PTT)
A postal, telegraph, and telephone service (or PTT) is a government agency responsible for postal mail, telegraph, and telephone services.

Power Over Ethernet (POE)
Power Over Ethernet (POE) is the ability to provide power to a device across a network cable without the need for a separate power cable.

Power Supply Unit (PSU)
A Power Supply Unit (PSU) is a separate cable and/or unit commonly with a UK mains plug used to power a device.

Primary Rate Interface (PRI)
Primary Rate Interface (PRI) is part of an Integrated Services Digital Network (ISDN) configuration. It works on a larger scale compared to Basic Rate Interface (BRI) and is utilised by large users/enterprises. A common term heard is the connection of a “PRI Card” on a phone system.

Private Branch Exchange (PBX)
A Private Branch Exchange (PBX) or telephone system is a control unit that primarily facilitates audio/video calls to a user’s site, or sites. Depending on its specification, a range of additional intuitive features can give users all the help they need during their calls: including queue announcements, live status monitoring, activity reports, automatic conversation recording and scheduled backup and reports.

Private Wide Area Network (PWAN)
A Private Wide Area Network (PWAN) is the joining of multiple broadband/ethernet connections to create robust and scalable network solution that is located in secure data centres with a centralised firewall.

A set of procedures in telecommunications connections that the terminals or nodes use to send signals back and forth.

Public Switched Telephone Network (PSTN)
Public Switched Telephone Network (PSTN) is a global term for the interconnection of public telephone networks over copper-based materials. They are primarily used for voice calls, fax machines, franking machines, card processing machines and connecting a modem for dial up internet (old technology). It is the foundation line for allowing DSL Services to operate.


Q Signalling (QSIG)
Q Signalling (QSIG) is the signalling protocol for ISDN which is utilised in Voice over IP (VoIP) networks and Virtual Private Networks (VPNs).

Quality Of Service (QOS)
Quality Of Service (QOS) is a feature configured on a device that can prioritise data traffic dependent on its use. For example, VoIP calls can be given a higher priority over web browsing/e-mail traffic.


Range Holder (RH)
A Range Holder (RH) is the communication provider that has been allocated a range of telephone numbers by OFCOM.

Remote Desktop Protocol (RDP)
Remote Desktop Protocol (RDP) is the ability for a user to connect to another computer utilising a graphical interface and a network connection.

Ability of a mobile user to access cellular services while away from the home network. This includes automated roaming between GSM networks, SIM-based roaming, where a user switches the SIM card into a mobile phone from a different network, or roaming across technologies. Roaming can take place within one country and across national boundaries. In a WLAN context, roaming occurs when a mobile device disassociates from one access point and then re-associates with a new access point. When roaming abroad, high charges can occur.

The router is a piece of hardware that allows two or more networks to be connected so that data can be transferred between them. The router sees and directs the data to the correct location. They are the crucial devices that let messages flow between networks.


This is a host computer on a network that stores information, such as websites, and responds to requests for information. A server responds to requests across a computer network to provide, or help to provide, a network service. Servers can be run on a dedicated computer, which is also often referred to as “the server”, but many networked computers are capable of hosting servers.

Service Set Identifier (SSID)
A Service Set Identifier (SSID) is a unique name which allows you to differentiate between other networks when connecting to a device over WiFi.

Session Initiated Protocol (SIP)
Session Initiated Protocol (SIP) is a method to which voice/video/messaging and other communication applications can initiate/maintain/modify and terminate real-time sessions between two endpoints on an Internet Protocol (IP) network.

Single Order Generic Ethernet Access (SOGEA)
Single Order Generic Ethernet Access (SOGEA) is your closest alternative to FTTC broadband and is available to order in many exchange areas. It is broadband, but without the requirement for an underlying PSTN line, which means the connection is more reliable with less chance of interference and instability.

Single Order Transitional Access Product (SOTAP)
Single Order Transitional Access Product (SOTAP) is a new product to replace ADSL connections. SOTAP delivers a copper path between the end user’s premises and the exchange infrastructure, providing a better experience for customers moving away from end of life WLR (Wholesale Line Rental) products. This is also only deliverable in certain areas at this moment in time but BT are working to broaden this reach.

SIP Trunking
SIP Trunking is the use of Voice over IP (VoIP) to facilitate connection of an existing telephone system to an IP telephony platform. Once connected, a business continues to operate their telephone system in the same manner to make and receive calls. SIP trunking provides customers with all the benefits of cutting-edge VoIP technology, without the need to replace a system they may just have invested in. By simply installing SIP trunking technology into their current telephone system, businesses can enjoy the highest quality voice communications, which is not only cheaper than traditional phone lines, but gives businesses the freedom to grow.

A softphone is a software programme (such as an app) enabling a user to make and receive calls through their device (computer, laptop, tablet or smartphone) rather than via a physical handset. These are frequently used to facilitate remote working.

Station Message Detail Record (SMDR)
Station Message Detail Record (SMDR) is a log of call detail made be an telephony endpoint.

This is when you watch or listen to a multimedia file as it’s downloading, such as when watching a film or listening to digital radio. It means you don’t have to fully download and save the file beforehand.

Symmetric Digital Subscriber Line (SDSL)
Symmetric Digital Subscriber Line (SDSL) is a type of Digital Subscriber Line (DSL) which transmits digital data over the copper wires of a telephone network. Speeds can vary dependent on location and product but can reach up to 22.5Mb/s.


The Last Mile
The part of the network that runs from the exchange to the customer’s premises. Despite the name, the last mile can be over 100 miles long.

This term refers to internet service providers deliberately slowing down (or throttling) internet connections to certain customers and/or at certain times. It is also referred to as ‘traffic management’ or ‘traffic shaping’. It is most commonly employed during peak broadband usage times and against customers deemed to have overstepped their usage cap or fair usage policy terms. These measures are often temporary and used as a deterrent against those downloading large amounts of data.


Unified Messaging (UM)
Unified Messaging (UM) is the integration of different media types into a single interface accessible from multiple devices. An example of UM is Voicemail within a phone system.

Uninterruptable Power Supply (UPS)
An Uninterruptable Power Supply (UPS) us a secondary device that can supply power for a limited period while the primary power supply/feed is disrupted.

Upload Speed/Upstream
This term describes how fast your broadband connection can send data from your computer. A good example of uploading is sending your photos to an online website or portal, or sending emails. Anything that goes across the internet from your computer is considered to be ‘uploaded’. Similarly, anything coming in the other way is being ‘downloaded’ (anything from getting your emails or a web page to live streaming television).


Virtual Private Network (VPN)
A Virtual Private Network (VPN) is a link over the internet between multiple sites with increased security in comparison to standard internet transmissions.

Voice over Internet Protocol (VoIP)
Voice over Internet Protocol (VoIP) is method to which voice calls route over the internet. This term is interchangeable with ‘Hosted’.


A Wide Area Network (WAN) is a network that connects multiple broadband/ethernet connections over a large geographic area.

Wholesale Line Rental (WLR)
Wholesale Line Rental (WLR) allows service providers to brand themselves over the Public Switched Telephone Network (PSTN). BT Openreach (in the UK) ultimately maintain and repair the lines however service providers (such as Premier Choice) can supply services to their clients without having to maintain the network itself.

WiFi is the technology that allows a wireless connection to the internet.

Wi-Fi Protected Access (WPA) 3 is the third generation security certification standard, designed to improve security for wireless networks.