noun
private automatic branch exchange; PABX; PBX
Technical computing term for a private telephone exchange that automatically connects internal calls and routes external calls.
このビルには自動式構内交換機が設置されている。
A private automatic branch exchange is installed in this building.
A broader term for any private branch exchange, not necessarily automatic.
Compound of 自動式 (automatic type), 構内 (premises), and 交換機 (exchange device).