What Does Internet Protocol Private Branch Exchange Mean?
Internet Protocol Private Branch Exchange (IP PBX) is a PBX system that is built over IP-based architecture for delivering and managing voice communication services.
IP PBX provides IP telephony and switching services between an IP telephone network and a public switched telephone network (PSTN) system.
Techopedia Explains Internet Protocol Private Branch Exchange
IP PBX is designed to provide similar functionality to that of traditional PSTN-based PBX systems. IP PBX can be built or provided by a telecom operator, a third-party Internet service provider or it can be hosted in-house. Unlike PSTN PBX, IP PBX has the ability to switch, forward and route the calls between VoIP networks to PSTN and PSTN to VoIP. IP PBX services are largely delivered and managed through purpose-built software with supporting switches and network devices. Hosted PBX and virtual PBX are among the delivery modes of IP PBX system.