Cloud Communications Terms in Plain English

As new technology is developed and released, new terms enter the conversation. New, frequently confusing terms. While there are several sources for a comprehensive glossary, we realize most of them are overkill.

You need to know what’s being discussed, not the entire history of electronics, communications, the Cloud, VoIP, telephony, and PBX, not to mention SIP trunks…

Here’s what you need to stay in the conversation and disarm the techo-babble:


Business Process as a Service is a form of business process outsourcing that uses a Cloud computing service model. The process takes place in the Cloud, not on a local computer. Some examples are payroll services and business travel services. Find more information at Technopedia.

Business Messaging

Group notifications and messaging using the internet, email and dial-up phones, frequently with SENT, DELIVERED and READ confirmations.

Cloud Communications

Internet-based voice and data communications where applications, switching and storage are hosted in a private or public Cloud and accessed over the Internet. This includes: phone, voicemail, messaging, presence, conferencing and mobility features. Find more information at

Cloud Computing

Using a network of remote servers (the Cloud) via the Internet to store, manage and process data, rather than a local server or a personal computer. Amazon Web Services offers some videos and in-depth information.

Cloud PBX

A phone system that is hosted offsite in a secure location and delivered via the cloud/internet rather than a box of wired connections onsite that must be powered, insured and maintained. Browse the free white paper, The Case for Cloud Communications for more information.


A firewall is a network security system that monitors and controls the incoming and outgoing network traffic based on predetermined security rules. Think of it as a digital wall with digital barbed wire on top to keep the internet vandals out.

Hybrid Communications Deployment

Hybrid cloud uses a mix of on-premises, private cloud and public cloud services with orchestration between the platforms allowing them to work together. Hybrid is frequently the solution when an existing phone system is in place but new capabilities like conferencing or unified messaging are desired. Get a better idea about how hybrid cloud communication solutions work at the For Dummies website.

Hybrid IT

An approach to enterprise computing in which an organization provides and manages some information technology resources in-house but uses cloud-based services for others. TechTarget offers more about Hybrid Cloud IT.


Infrastructure as a Service. A form of cloud computing that provides virtualized computing resources over the Internet; the basic form of Cloud computing. Wikipedia provides more depth and history on IaaS.


A Key Service Unit is a small scale version of a PBX, offering limited functionality but a lower cost. A KSU is typically found when a location has fewer than 40 users.


Multiprotocol Label Switching. This is a system of sharing data between multiple sites on a private network. MPLS is a key technology in speeding up your communications system. TechTarget goes into more depth on the subject, but be prepared to put on your propeller hat.

On-prem / On-premise

Services or equipment that exists behind a firewall, and is managed within an organization’s facility – in the building.


Over the Top. VoIP services running across an organization’s internet connection. If you have the bandwidth available, providers can provide a full suite of communication services – voice, mobility, messaging, presence, conferencing, and even a Contact Center – via your internet connection.


Platform as a Service is a type of cloud computing that allows customers to develop, run, and manage web applications without the cost and complexity of building and maintaining the required infrastructure. A more in-depth description can be found at Search Cloud Computing.


Private Branch Exchange. The automated switching machine that replaced the phone operator manually connecting calls in large businesses. Somewhere in the basement or out back of your building stands a PBX and all its wires. Want to add a new phone? Wire it in through the PBX. Wikipedia can tell you more.


The access points on equipment to deliver voice or data services.


Availability or display of availability, based on login status and triggers such as use of keyboard and mouse. Where is everyone – real time? Presence keeps you in touch without sharing the same office. Learn more about the benefits on our Presence features webpage.

Private Cloud

A type of cloud computing that delivers similar advantages to public Cloud, including scalability and self-service, but through a proprietary architecture privately owned by the business or an affiliate. A private cloud is frequently deployed for security or compliance reasons.

Public Cloud

The standard cloud computing model, in which a service provider makes resources, such as applications and storage, available to the general public over the Internet. Mashable provides a good beginner’s guide to the Cloud.


The device that forwards data packets along networks. You probably have one in your home connected to a cable or phone line.


Software as a Service is a software licensing and delivery model in which the software is licensed on a subscription basis and is centrally hosted – typically in the Cloud. Salesforce is an example of software as a service.


Software Designed Networking is an approach to computer networking that allows administrators to manage services through abstraction of higher-level functionality. Got that? SDN technology allows improved control over your computer network resources – much less waste, while improving overall flexibility and performance. Still curious? The Open Networking Foundation can provide an in-depth look at SDN.

SIP Trunking

The VoIP and streaming media service by which a service providers delivers telephone services and unified communications to customers. Visit our SIP Trunking webpage for a high-level overview.


Software that allows a user to make telephone calls over the Internet via their computer. Any internet-connected device with a microphone and speakers or a VoIP headset can become a softphone: a laptop, desktop, tablet, etc.


A device that channels incoming data from any of multiple input ports to the specific output port that will take the data toward its intended destination. Moving the call to the right destination. Wikipedia provides more information.


Time Division Multiplexing is the term used for wire-based digital telephone systems. TDM phones have a dedicated wire from the telephone jack directly to the telephone system’s KSU or PBX.  Cloud communications replaces this traditional technology with voice over internet protocol (VoIP) and a cloud PBX.


Unified Communications – The integration of real-time communication services such as instant messaging, presence information, voice, mobility features, audio, web & video. Read our free white paper on unified communications – UC is actually all about the user experience.


Unified Communications and Collaboration. The service brings together the communications tools that people use daily such as voice, e-mail, instant messaging, presence, click-to-dial, conferencing and video into a single interface. Another term for Unified Communications. Visit our webpage for more on unified communications.


Unified Communications as a Service. A service model in which a variety of communication and collaboration applications and services are outsourced to a third-party provider and delivered over the internet for a monthly fee. Read our free white paper on how to reduce operational costs with UCaaS – is it right for you?


Voice over Internet Protocol. Voice services delivered over the internet or from a private cloud rather than dedicated phone wire infrastructure.


Real Time Communications delivered within a web browser via the public internet. The WebRTC organization leads the development of this open framework technology.