What Is PBX?

PBX stands for Private Branch Exchange, a telecommunication system designed for businesses and organizations.

A PBX manages internal and external communications by creating an internal telephone network. The purpose of a PBX is reduce the number of inbound phone lines; instead, the phone system is designed around the number of calls that will be made at the same time. Then, the PBX has only the number of phone lines necessary to make all those calls

Traditionally, a PBX was a manual phone system, run by switchboard operators. Today, packet switching technology allows the process of connecting phones within a phone system to be automated.

A VoIP PBX is a PBX that uses VoIP to supply phone service.

Circuit-switched networks are still used for PBXs. However, VoIP PBX is much cheaper and more efficient than traditional landline communication. VoIP sends data and voice together over the Internet, using less bandwidth in a connection.

PBX Systems will either be held on-premises of the business or be hosted by a VoIP provider. PBX gives extensions to employees or departments instead of using separate phone lines.


On-premises VoIP PBX is called IP PBX. An IP PBX phone system requires a business to run and maintain its own hardware, which will run a data network with Internet Protocol and also interact with the public switched telephone network.

Alternatively, there is on-premises PBX using software, called digital PBXFeatures and functions are run digitally rather than through switching and network hardware, but the business must still maintain the system.

Recent Reviews

Intermedia logo

We started using Intermedia at the beginning of this year, and thus far it has performed like a business phone system should. We've had no...

October 11th, 2017 - JJ2424
centurylink logo

We have had the worst experience with CenturyLink, do not bundle anything with them. When we moved they promised that they could give us internet at...

October 6th, 2017 - Tammiestefan

Most Recent Blog Posts

office worker dialing phone system
This Week in Telecom: October 13th

This Week in Telecom is a bi-weekly news round-up on VoipReview.org that aims to give our readers a fast and easy way to catch up on the latest news and top stories that are trending in the voice and...

Oct 13, 2017
Avaya Equinox Meetings Online laptop tablet interfaces
How Avaya is Transforming the Enterprise Video Experien...

A common adage is that a picture is worth a thousand words. But when it comes to business, video could be worth a whole lot more. Organizations of all sizes are discovering the tremendous benefits of...

Oct 09, 2017