pbx
nounUK /ˌpiː biː ˈeks/
US /ˌpiː biː ˈeks/
A PBX is a special phone system that helps many people in one building talk to each other and to the outside.
The office uses a PBX to connect all its phones.
OTHER MEANINGS
2. A private telephone network used within an organization that lets internal calls connect and shares outside lines.
The company installed a new PBX to manage its growing number of extensions.
3. Software that provides telephone switching functions over the internet, often called an IP PBX.
Their IP PBX lets employees make calls through their computers.
4. A switchboard or exchange that routes calls between internal extensions and external lines.
The receptionist answered through the PBX and transferred the call.