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.
A PBX (Private Branch Exchange) is a system that connects telephone extensions to the Public Switched Telephone Network and provides internal communication for a business. An IP PBX is a PBX with Internet Protocol connectivity and may provide additional audio, video, or instant messaging communication utilizing the TCP/IP protocol stack.
VoIP gateways can be combined with traditional PBX functionality to allow businesses to use their managed intranet to help reduce long distance expenses and take advantage of the benefits of a single network for voice and data (converged network). An IP PBX may also provide CTI features.
An IP PBX can exist as a physical hardware device or in software.