digital phone service

In the field of telecommunications, a telephone exchange or central office houses equipment that is commonly known as simply a switch, which is a piece of equipment that connects phone calls. It is what makes phone calls "work" in the sense of making connections and relaying the speech information.

The term exchange can also be used to refer to an area served by a particular switch, (this was known as a wire center under the Bell System. More narrowly, it can refer to the first three digits of the local number. In the three-digit sense of the word, other obsolete Bell System terms include office code and NNX. Digital Phone Service - Broadband Phone Service - VoIP Provider - You're paying too much for your Toll Free Service. In the United States, the word exchange can also have the technical meaning of a local access and transport area under the Modification of Final Judgment (MFJ).

Historic perspective

The first telephone exchange opened in New Haven, Connecticut in 1878. The switchboard was built from "carriage bolts, handles from teapot lids and bustle wire" and could handle two simultaneous conversations (see National Park Service).

Later exchanges consisted of one to several hundred plug boards manned by operators. Call anyone, when you want, as often as you want,.