Definition - What does IP PBX mean?
IP PBX is also known as IP-Enabled PBX.
Techopedia explains IP PBX
Over time, PBX systems became connected to Voice over Internet Protocol (VoIP) elements. New IP PBX systems often include helpful tools for video conferencing and combining voice and data services. Some of these include mobile telecommunication setups, as well as public telephone setups. Using strategies like Session Initiation Protocol (SIP) trunking, these telecom systems offer companies a broad infrastructure and sometimes help consolidate billing or streamline business processes.