PBX OperatorsPBX operators became differentiated from common carrier operators when the telephone became a common business tool in the 1920s. Operators would manage calls into and out of the office with a switchboard, a electromagnetic device that requires the operator to plug telephone lines into their destination telephone wires by hand. In the late 1960s, the switchboard began to be phased out in favor of the automatic exchange, an early electric telephone line manager. Since the early 1990s, PBX operators began working with computerized electronic automatic branch exchanges.
Modern PBX operators have started to use VoIP branch exchanges and Integrated Services Digital Networks exchanges that use Internet Protocols to receive, connect and transfer calls. Both these networks allow the PBX operator to mechanize more operations, such as call forwarding, conference calling and caller ID. These new digital branch exchange frameworks are also lowering the cost of running a PBX due to their inexpensive components.