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The North American Numbering Plan (NANP) is an integrated telephone numbering plan of 24 countries and territories: the United States and its territories, Canada, Bermuda, and 16 Caribbean nations. It is a system of numbering plan areas (NPA) with three-digit area codes and seven-digit telephone numbers that directs telephone calls to particular regions on a public switched telephone network (PSTN), where they are further routed by the local network.
Posted by waqasahmad
en.wikipedia.org/wiki/NXX
Posted by crouse
refers to the 1st six digits of a phone no derived from NANP
Posted by Hash007
Number exchange. Usually corresponds to the prefix in the traditional POTS-PSTN telephone numbering system.
Posted by tyson
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