An IP (Internet Protocol) PBX (Private branch exchange) is a PBX that provides audio, video, and instant messaging communication through the TCP/IP protocol stack for its internal network and interconnects its internal network with the Public Switched Telephone Network (PSTN) for telephony communication.
It is used in LTE for VoIP communications. VoIP (Voice over Internet Protocol) gateways can be combined with traditional PBX functionality enabling businesses to use their managed intranet to help reduce long distance expenses, enjoy the benefits of a single network for voice and data and advanced CTI features or be used on a pure IP system which in most cases give greater cost savings, greater mobility, and increased redundancy.
An IP-PBX can exist as a hardware object, or virtually, as a software system.
