PBX/ PABX Systems

What is PBX/ PABX?

To learn more about a PBX, PABX

PBX stands for Private Branch Exchange, PABX stands for Private Automated Branch Exchange (also commonly know as a Switchboard or Phone System), which is a privately owned telephone network call switching system used within a company, office or organization.

A PBX or Private Branch Exchange is the part of a private telephone system that manages phone calls both internally and externally for an organisation.

The PBX was developed to provide large companies a cost reduction in their telecommunications bill by letting them handle their own telephone system routing while still providing a telephone line for calling outside the companies network to the public switched telephone network (PSTN).

A PBX essentially takes the place of the phone companies central office by acting as the exchange point, routing phone calls.

With the PBX in place, each phone only needs an extension, and not a phone number. A PBX handles all calls made between desk to desk within the company. When an outside call is required an access number is dialled first (Usually a 0). The PBX then transfers the call to the phone companies central office. From there the phone call is routed to the various telephone network providers.

A PBX reduces costs because the company only pays for the number of phone lines liable to be connected at any given time to the outside. If a company has 100 phone extensions, it is unlikely that everyone will be making an outside call at once. Perhaps 10% will require an outside line at any given time. Therefore the business will rent 10 phone lines from the phone company, instead of 100 phone lines.

A PBX can be located on premise, in the cloud or through a hybrid of the two. From a technology perspective there are four different types of phone or end points on a PBX. Analogue, Digital, Voice over IP (VoIP) or session initiation protocol (SIP).