Coba jelasin See also dari Sentral telepon dalam bahasa sunda dong

Full Availability, Limited Availability and Gradings

PBX Private Branch Exchange or business-level switch

In US telecommunication jargon, a central office (C.O.) is a common carrier switching center Class 5 telephone switches in which trunks and local loops are terminated and switched.

Note:  In the DOD, "common carrier" is called "commercial carrier." Synonyms exchange, local central office, local exchange, local office, switching center (except in DOD Defense Switched Network (formerly AUTOVON) usage), switching exchange, telephone exchange. Deprecated synonym switch.