A-Z of Voice

The ultimate glossary for all telecommunication terms.


API (Application Program Interface) is a software intermediary between applications that allows them to communicate with each other. 


Augmentation is the process that allows organizations to extend their services in countries outside of ones that they have their infrastructure in.


Someone who receives a phone call from a caller.


Someone who originates a phone call.

Caller ID

General term which describes the presentation of a phone number (Caller ID number) and name (CNAM) of a caller to a callee.

Caller ID Number

The presentation of the phone number of the user or business to a callee within a Caller ID. The number can be changed to display the main number of the business rather than the original number of the caller.


A carrier is a service provider that connects phones allowing them to make and receive calls outside of their own private networks

Cloud Peering

Cloud Peering is the method that allows two networks to connect and exchange traffic directly without having to pay a third party to carry traffic across the Internet.


Stands for Caller ID Name. CNAM is the presentation of the name – not the number – of the user or business of the caller to a cellee within a Caller ID. CNAM can be 15 characters long and can consist of numbers, letters and spaces. Delivery of a CNAM by carriers is considered an optional feature hency its delivery to all callers can’t always be guaranteed.


CQP (Configure, Price, Quote) is software that helps companies accurately define the price of goods across a huge and constantly changing spectrum of variables. It is a term used in business to describe software systems that help sellers quote complex and configurable products.


Direct Inward Dialing (DID) is a telephone service that allows a phone number to ring through directly to a specific phone at a business instead of going to a menu or a queue and needing to dial an extension.

Direct Routing

Direct Routing is the process of routing Internet Services to the PSTN (traditional phone network).

It allows you to connect platforms such as Microsoft Teams and Zoom to telephone networks, allowing users to make and receive calls directly from their favourite collaboration suites.


E911 is a system used in North America that automatically shares a user’s location with emergency services in the case of a call to 911. The dispatcher’s computer receives information of the caller’s whereabouts from the telephone company, which are either the caller’s geographic coordinates (for wireless calls) or physical address (for landline calls). 


A failover is a back-up system that automatically comes online should the primary system fail. 

MOS Score

MOS Score is a measure used in the domain of Quality of Experience and telecommunications engineering, representing overall quality of a call.

Operator Connect

Operator Connect is an integration between Microsoft and carriers that serves as a tool to scale Direct Routing into a pure-cloud managed solution, with additional services such as billing, dashboards and analysis tools.

It’s a cost effective way for businesses to access voice through the internet, although it is generally less flexible than Direct Routing so it’s best suited for small businesses.

Operator Connect Accelerator 

SIPPIO’s fast-track program that allows carriers to become Operator Connect providers with fully configurable pre-built services and infrastructure.


PaaS (Platform as a Service) is a cloud computing model that provides customers a complete cloud platform—hardware, software, and infrastructure—for developing, running, and managing applications without the cost, complexity, and inflexibility that often comes with building and maintaining that platform on-premises.


PBX (Private Branch Exchange) is a private telephone network that allows users to call each other internally within a business or call external contacts from the business’ network, using different communication channels. 


Porting is the process of taking an existing phone number and transferring it to another provider. 


PowerShell is a task automation and configuration management program from Microsoft. It works with a command line shell and a scripting language integrated into the .NET framework, which can be embedded within other applications.


PSTN (Public Switched Telephone Network) is the traditional circuit-switched telephone network. PSTN comprises all the switched telephone networks around the world that are operated by local, national and international carriers. These networks provide the infrastructure and services for public telecommunication.


PUPM (Per User Per Month) is a contract that businesses can be signed to for systems that allocates a price per month based on every user that uses that system. 


SBC (Session Border Control) is a network function that secures voice over IP (VoIP) infrastructures while providing interworking between incompatible signaling messages and media flows (sessions) from end devices or application servers.


SIP (Session Initiation Protocol) is a signalling protocol that can be used to set-up and take down VoIP calls and can also be used to send multimedia messages over the Internet using PCs and mobile devices.

Zoom Phone

Zoom phone is the VoIP service developed by Zoom Video Communication Inc. Compared to a traditional PSTN line, Zoom Phones have even more services: Video-communication, Inbound Calls, Outbound Calls, Toll free number and even an internal unlimited and free routing.

Zoom Provider Exchange

Zoom Provider Exchange is a way to add external PSTN calling to Zoom Phone. Provider Exchange allows users to integrate their carriers into Zoom which makes them able to self-manage phone numbers provided by the partner to begin making calls.