Definition of PBX System

PBX is an abbreviation for private branch exchange. A PBX machine is a telephone system that serves a particular company. Usually, a company purchases a PBX machine to reduce the amount of telephone lines to be used.

Purpose

A PBX machine acts as a sort of telephone switch, as all phones within the company are wired to it. It is a system that connects employees with each other, as well as with callers outside the company.

Extension Numbers

With a PBX system, employees have a three- or four-digit extension number for anyone--co-workers and outside callers--to reach them.

Outside Calls

An employee would have to dial a single-digit outside access code--which is usually the number nine--before the company's phone number in order to reach someone outside the company.

Restriction

Since a PBX system serves a particular company, the telephone system can only be accessed or used by its employees, and no one else.

Significance

PBX systems eliminate the need for installing individual phone line for each company employee. Thus they are relatively cost-effective and convenient.

References

• Tech-faq.com: PBX
• PBX/Key Systems and LAN Telephony
• Webopedia.com: PBX