PBX vs. PC/PBX - a quick comparison

A PBX (private branch exchange) is a telephone system within an enterprise that switches calls between enterprise users on local lines while allowing all users to share a certain number of external phone lines. The main purpose of a PBX is to save the cost of requiring a line for each user to the telephone company's central office. The PBX is owned and operated by the enterprise rather than the telephone company (which may be a supplier or service provider, however). Private branch exchanges used analog technology originally. Today, PBXs use digital technology (digital signals are converted to analog for outside calls on the local loop using POTS).

A PBX includes: telephone trunk (multiple phone) lines that terminate at the PBX; a computer with memory that manages the switching of the calls within the PBX and in and out of it; the network of lines within the PBX; usually a console or switchboard for a human operator.

In some situations, alternatives to a PBX include Centrex service (in which a pool of lines are rented at the phone company's central office), key telephone systems, and, for very small enterprises, primary rate ISDN.

The term PC/PBX has been coined throughout the industry to describe an all inclusive telephone system based solely on PC technology. Server products have been designed as low-cost, high feature replacements for the higher priced traditional PBX systems. The communication server is a stand-alone high reliability machine that in most instances takes all of the individual capabilities of telephony and rolls them into one seamless product.

ACD (automatic call distribution), Auto-attendant, Voice mail, Unified messaging, FAX, Call routing, Networking, etc. are all built into most products on the market. And, since it is based on the open, modular architecture of the PC it is also highly scaleable. Need to double in size and or capacity? Simply add another server to the network. Moves, additions, and changes are also seamlessly integrated into simple to use management interfaces.