Jargon Buster


ADSL – Asynchronous Digital Subscriber Line

Allows data transmission along standard telephone wires. ADSL has a higher data download speed than it has upload, ranging from 256k/s to 24mb/s.

Call Management

A general term used to describe the process of determining the manner in which telephone calls are handled and their ultimate destination. Usually used with respect to incoming calls, i.e. calls received by an organisation.

CLI – Calling Line Identity

CLI is a telephone service that transmits a caller’s number to the called party’s telephone. Where available, CLI can also provide a name associated with the calling telephone number.

CRM – Customer Relationship Management

A business philosophy that involves anticipating, understanding and responding to customer needs whilst maximising profits.

DDI – Direct Dial Inbound

A service whereby a call made to a DDI number can be routed directly to an internal extension without intervention by a switchboard operator.

DECT – Digital Enhanced Cordless Telecommunications

DECT (Digital Enhanced Cordless Telecommunications) is a digital wireless telephone technology, DECT uses time division multiple access (TDMA) to transmit radio signals to phones. Whereas GSM is optimized for mobile travel over large areas, DECT is designed especially for a smaller area with a large number of users, such as in cities and corporate complexes. A user can have a telephone equipped for both GSM and DECT (this is known as a dual-mode phone) and they can operate seamlessly.

DSL – Digital Subscriber Line

Allows data transmission along standard telephone wires. Using a higher frequency than normal voice traffic, DSL comes in two flavours. ADSL (Asynchronous DSL) has a higher data download speed than it has upload, ranging from 256k/s to 24mb/s. SDSL (Synchronous DSL) is used less frequently and allows the same transmission speed for both upload and download.

Fibre Optics

When light is transmitted over high purity, thin fibres of glass. This gives fibre optic cable a far superior bandwidth than conventional cable or copper wire.

Fibre To The Cabinet (FTTC)

This is a generic term for any broadband service that uses fibre optic cable instead of traditional copper wiring to connect a telephone exchange to the ‘green cabinets’ on surrounding roads.

GPRS – General Packet Radio Service

General Packet Radio Services (GPRS) is a packet-based wireless communication service that promises data rates from 56 up to 114 Kbps and continuous connection to the Internet for mobile phone and computer users. The higher data rates allow users to take part in video conferences and interact with multimedia Web sites and similar applications using mobile handheld devices as well as notebook computers. GPRS is based on Global System for Mobile (GSM) communication and complements existing services such circuit-switched cellular phone connections and the Short Message Service (SMS).

GSM Network

Global System for Mobile communications – the standard for digital cellular phone services across the UK, Europe and many other countries.

Hardware Platform

The physical electronic system comprising one or more computers (usually referred to as servers) on which software is run to provide the service or solution required.

Hosted Service

In the context of telephony, the term refers to the provision of a telephony service where the functions normally fulfilled by a PBX on the customers’ premises (see CPE) are provided by a system housed remotely, owned and managed by a service provider. The hosted service will be shared between a large number of customers.

Hunt Group

Multiple phones grouped by a single extension number which enable a call to be answered by anyone in the hunt group. The calls will ‘hunt’ from one phone to another until answered.


A telephone switching system that uses a signaling system based on the Internet Protocol as opposed to traditional PBXs that are based on a Time Division Multiplex (TDM) protocol.

IP Telephony

A telephone system that operates over a data network using the Internet Protocol.

IP phone

A telephone that plugs into your network rather than a telephone line and uses IP to make and receive calls.

ISDN – Integrated Services Digital Network

The key feature of the ISDN is that it integrates speech and data on the same lines, adding features that were not available in the ‘classic’ telephone system.

IVR – Interactive Voice Response

A system where a caller uses their telephone keypad to respond to computer generated voice prompts. The simplest form of IVR system is an Auto Attendant where the caller’s keypad choices determine the ultimate destination of their call. In the more complex form of IVR, the telephone system is connected to one or more external database. A typical example here is telephone banking, where callers are able to find out the balance in their account or even transfer funds from one account to another.

Leased Line

A service contract between a provider and a customer, this means the provider would deliver a symmetric telecommunications line connecting two or more locations in exchange for a monthly rental fee. Leased lines can be used for data, telephone or internet services.

Local loop unbundling (LLU)

This is the regulatory process of allowing multiple telecommunications operators to use connections from the telephone exchange’s central office to the customer’s premises. The physical wire connection between customer and company is known as a ‘local loop’, and it is owned by the incumbent local exchange carrier. To increase competition, other providers are granted unbundled access. Calls are re-routed by using a ‘smart-box’ or a four-digit code to an alternative provider.

Number Porting

An agreement which allows telephone numbers to be moved between telecoms companies.

Operating system

software than controls how all the hardware and applications on a computer system run and work with each other. The best-known are Microsoft Windows and Apple MAC on PC systems, and Android and IOS (Apple) on smart phones and tablets.

PBX/PABX – Private (Automatic) Branch eXchange

The switching system within an organisation that connects calls between internal telephones or between internal telephones and external phones connected via the Public Switched Telephone Network. Also referred to as a PABX (Private Automatic Branch eXchange) but, since all present day switching systems are automatic, the terms are now used interchangeably.

PoE – Power over Ethernet

Power over Ethernet technology is a system to transmit electrical power, along with data, to remote devices over standard twisted-pair cable in an Ethernet network. This technology is useful for powering IP telephones, wireless LAN access points and other appliances where it would be inconvenient, expensive or infeasible to have a separate power supply.


Allows you to set a status on a phone or in software (e.g. ‘In a meeting’, ‘out of town’, ‘at lunch’). The status will show when an internal caller dials your phone. It can also be visible to your receptionist or whoever runs the software to so they can see the status of all phones in the system.

PSTN – Public Switched Telephone Network

Public Switched Telephone Network, refers to the international telephone system based on copper wires carrying analog voice data. This is in contrast to newer telephone networks base on digital technologies, such as ISDN, IP, ATM and FDDI.
Telephone service carried by the PSTN is often called plain old telephone service (POTS).

QoS – Quality of Service

Quality of Service is the ability to provide different priority to different applications, users, or data flows, or to guarantee a certain level of performance to a data flow.

Servers / Preconfigured Servers

A computer system that, typically, runs some software to perform a specific task or set of tasks. See also Hardware Platform.

SIM – Subscriber Identity Module

SIM cards securely store the service-subscriber key or IMSI (see above) used to identify a subscriber. The use of SIM cards is mandatory in GSM devices.

SIP – Session Initiation Protocol

SIP is a signaling 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.

SMS – Short Message Service

SMS is a communications protocol allowing the interchange of short text messages (up to 160 characters) between mobile telephone devices.

Soft phone

A software application that will run on a PC/laptop, tablet, or smart phone, providing an extension onto a PBX system over Internet Protocol (IP).

Telephone conference

Sometimes also known as a teleconference, it allows a large number of people to participate on a telephone call. They are also commonly used with special telephone conference phones in boardrooms.

Unified Messaging

A solution that brings together different types of electronic messages (e.g. voice, fax, video, email) into a single mailbox or inbox, making it more convenient for the user to access.

URL – Uniform Resource Locator

The address of a page on a website, e.g. www.tpsl.co.uk is the URL of the home page on the tpsl website.
Video Conferencing
Allows a number of people to participate in a remote meeting including video feeds for some or all of the participant and very often include content/desktop viewing.

VoIP – Voice over IP

VoIP (Voice over Internet Protocol) is the transmission of voice traffic over IP-based networks. This could be publically, over the internet or privately over a managed IP network.

VPN – Virtual Private Network

A process whereby software is used to create what appears as a private network running over a public network. VPNs are typically used to extend an organisation’s internal computer network to off-site locations such as branch offices and to home-based employees.


Very-high-bit-rate Digital Subscriber Line. Upload and download speeds can be faster and higher bandwidth may better performance, dependent on conditions and distance.

Voice Mail

The ability to receive information direct from a caller when you are unable to answer the telephone. Extremely versatile it allows you, as a basic feature, to provide callers with a personalised greeting and to give them the option of leaving a message. It is also possible to offer callers the opportunity to speak to an operator or a colleague.