a
reference to a telephone
exchange in
Phoenix,
Arizona, USA. An
exchange is a
facility where the telephone
lines of an
area are connected and phone calls are routed; it also refers to the geographical
area (such as a city or neighborhood) serviced by the
exchange. In earlier methods of telecommunications, a person would make a phone call by first dialing the
numbers corresponding to the first two or three letters of the
exchange name, followed by the rest of the phone number. For
example, to connect with the Alpine
exchange in
Phoenix, a person would
dial the
numbers on a telephone corresponding to "AL," specifically "2" and "5," and then the rest of the phone number to
reach the person he wished to talk to.