What does NANPA stand for? 

NANPA

The North American Numbering Plan (NANP) is a telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1 and has the international calling code 1. Some North American countries, most notably Mexico, do not participate in the NANP. The concepts underlying the NANP were originally devised in the 1940s by the American Telephone and Telegraph Company (AT&T) for the Bell System and the independent telephone operators in North America. The goal was to unify the diverse local numbering plans that had been established in the preceding decades, speed call completion times, and reduce costs for toll calls, by reducing or eliminating manual labor by telephone operators, and eventually prepare the continent for direct-dialing of long-distance calls by customers. Direct dialing became possible in 1951 in a first trial, and was expanded across the nation in the decade following. AT&T continued to administer the numbering plan and the technical infrastructure until the breakup of the Bell System, when administration was delegated to the North American Numbering Plan Administrator (NANPA), a service that has been procured from the private sector by the Federal Communications Commission (FCC) in the United States. Each participating country forms a regulatory authority that has plenary control over local numbering resources. The FCC also serves as the U.S. regulator. Canadian numbering decisions are made by the Canadian Numbering Administration Consortium.The NANP divides the territories of its members into numbering plan areas (NPAs) which are encoded numerically with a three-digit telephone number prefix, commonly called the area code. Each telephone is assigned a seven-digit telephone number unique only within its respective numbering plan area. The telephone number consists of a three-digit central office (or exchange) code and a four-digit station number. The combination of an area code and the telephone number serves as a destination routing address in the public switched telephone network (PSTN). The North American Numbering Plan conforms with International Telecommunication Union (ITU) Recommendation E.164, which establishes an international numbering framework.

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