Understand VoIP terminology

This glossary serves as your comprehensive guide to the essential terminology associated with VoIP. Whether you're a business professional seeking to optimise communication infrastructure or a curious individual exploring the intricacies of telephony, understanding these terms is crucial for harnessing the full potential of VoIP technology. From the fundamental concepts like IP addresses and protocols to the intricacies of audio conferencing, codecs, and call duration, we'll demystify the language of VoIP and equip you with the knowledge to navigate this transformative landscape.

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Glossary of terms

Audio Conferencing

Audio conferencing enables multiple participants to engage in a telephone call simultaneously, facilitating collaboration and communication.


Bandwidth refers to the maximum rate of data transfer across a network. It determines the capacity of a communication channel and influences the speed at which data can be transmitted.

Call Duration

Call duration is the total length of time a phone call or communication session lasts from initiation to termination.

CNAM (Caller ID Name)

CNAM is a feature that displays the name of the calling party on the recipient's phone during an incoming call.


Codec (Coder-Decoder) is a device or software that compresses and decompresses audio or video data for transmission and playback. It is essential in maintaining efficient data transfer.


Compression is the process of reducing the size of data to save storage space or transmission bandwidth. In telecommunications, compression techniques are used to minimise the amount of data transmitted without significant loss of quality.

Conference Bridge

A conference bridge is a device or software application that enables multiple participants to join a teleconference, facilitating group communication.

CSR (Customer Service Representative)

A CSR is an individual who interacts with customers on behalf of a company, addressing inquiries, resolving issues, and providing information about products or services.

Dial Plans

Dial plans are sets of rules defining how phone calls are routed within a telecommunications network, specifying the sequence of digits required for call setup.


Find-Me/Follow-Me is a feature that allows users to define a sequence of phone numbers where they can be reached, ensuring calls follow the user to different locations or devices.

Fixed Mobile Convergence

Fixed Mobile Convergence (FMC) is the integration of fixed-line and mobile telecommunications networks, allowing seamless communication across both platforms.

Internet Congestion

Internet congestion occurs when network traffic exceeds the capacity of the available resources, leading to slowdowns or disruptions in data transmission.

IP Address

An IP (Internet Protocol) address is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. It serves two main purposes: host or network interface identification and location addressing.

IVR (Interactive Voice Response)

IVR is a technology that allows interaction between users and a computerised system through voice or keypad inputs. It is commonly used in phone systems to facilitate automated customer service.


Jitter is the variation in the delay of received packets in a communication network. In VoIP and other real-time applications, jitter can lead to uneven audio or video playback.

kbps (Kilobits per Second)

Kbps is a unit of measurement for data transfer speed, indicating the number of kilobits transmitted or received per second.

LAN (Local Area Network)

LAN is a network that is limited to a small geographic area, such as a single building or campus. It enables the connection of computers and devices for local communication and resource sharing.


Latency is the time delay between the initiation of a process and its completion. In telecommunications, latency can impact the responsiveness of real-time applications.


Messaging involves the exchange of messages between individuals or devices. It can include various forms such as SMS, instant messaging, and email.


Origination refers to the initiation or starting point of a communication, such as the origination of a phone call or data transmission.

Packet Loss

Packet loss occurs when data packets transmitted in a network do not reach their destination. It can lead to degraded quality in voice or video communications.


Porting involves transferring a phone number from one service provider to another or between different types of services.


A protocol is a set of rules and conventions that govern the communication between devices in a network. It defines the format, timing, sequencing, and error control of messages exchanged over the network.

PSTN (Public Switched Telephone Network)

PSTN is the traditional circuit-switched telephone network that provides public telecommunication services using copper and fibre-optic cables. This is changing in 2025, so make sure you know everything about the switch from PSTN.


Real-time refers to systems or processes that respond to events or inputs immediately, with minimal delay. In telecommunications, real-time communication occurs without noticeable delay, providing instantaneous interaction.

Sample Rate

Sample rate is the number of samples of a signal taken per unit of time. In telecommunications, it often refers to the rate at which audio data is captured or played back.

Service Provider

A service provider is a company or organisation that delivers specific services, such as internet access, telecommunication services, or cloud computing resources.

SIP (Session Initiation Protocol)

SIP is a signalling protocol used for initiating, maintaining, modifying, and terminating real-time sessions that involve video, voice, messaging, and other communications and application sessions.

SMS (Short Message Service)

SMS is a text messaging service that enables the exchange of short text messages between mobile devices. It is widely used for communication and is a standard feature on most mobile phones.

TCP (Transmission Control Protocol)

TCP is one of the main protocols in the Internet Protocol suite, providing reliable, ordered, and error-checked delivery of data between applications running on hosts connected by a network.


Telephony refers to the technology and methods used for voice communication over a distance, encompassing traditional telephone systems as well as modern VoIP technologies.


Termination refers to the conclusion or end of a communication session, such as the termination of a phone call or data transmission.

VoIP Gateway

A VoIP gateway is a device that converts traditional telephone signals into digital data for transmission over an IP network, facilitating the integration of VoIP with conventional telephony systems.

VoIP PBX (Voice over IP Private Branch Exchange)

VoIP PBX is a private telephone network within an organisation that allows for VoIP communication, providing features similar to traditional PBX systems.

VoIP Phone

VoIP (Voice over Internet Protocol)phone is a technology that allows voice communication and multimedia sessions over the Internet, enabling telephone calls to be made using the Internet rather than traditional telephone lines.

WAN (Wide Area Network)

WAN is a network that covers a broad area, typically spanning cities, countries, or even continents. It connects multiple LANs and facilitates the exchange of data between geographically distant locations.

Web Browser

A web browser is a software application that allows users to access and view information on the World Wide Web. Examples include Chrome, Firefox, Safari, and Edge.

XMPP (Extensible Messaging and Presence Protocol)

XMPP is a communication protocol for messaging and presence information exchange, commonly used for instant messaging.

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