What is a PBX?



Learn about PBX Maintenance & Support:

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

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 or PSTN.

A PBX can be located on premise, in the cloud, or through a hybrid of the two. Generally speaking cloud based systems are no longer referred to as a PBX but as a Unified Communication (UC) solution or UC as a service (UCaaS).

From the technology perspective, there are four different types of phones or end points on a PBX: Analog, Digital, Voice over IP, and Session Initiation Protocol (or SIP). A PBX takes one or more of these languages and translates it so that the PSTN can understand and connect calls. To get to the PSTN, a PBX must use either a telecommunications service provider (TSP) or an internet service provider (ISP) such as AT&T, CenturyLink, Sprint, etc.

The PBX reduces costs by sharing trunk lines between multiple stations. Instead of subscribing to 100 trunk lines for 100 stations, a PBX delivers multiple stations for only one trunk line.

Maintaining and updating an organizations’ PBX is an important part of keeping an organization connected. The PBX serves as a critical component of an organization’s telephone network, so minimizing system downtime is utterly vital, which includes continually keeping the network’s software up to date. Complex PBX systems often require professional telephony engineers to diagnose and fix problems, which is why many companies choose to form an ongoing maintenance relationship with a specialized PBX service provider.

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