Search results
Results From The WOW.Com Content Network
Telephone number pooling, thousands-block number pooling, or just number pooling, is a method of allocating telephony numbering space of the North American Numbering Plan in the United States. The method allocates telephone numbers in blocks of 1,000 consecutive numbers of a given central office code to telephony service providers.
The solution for expanding the numbering pool within an NPA was to remove the restriction posed by not using 0 and 1 in the middle position of central office codes. This made central office codes interchangeable. An interchangeable NPA code and an interchangeable central office code is a code that permits any of the ten numerals in the middle ...
Central office code protection was once common in communities on provincial or state boundary lines. It has been declining in use as inefficient allocation of numbering resources to the growing number of competitive local exchange carriers has caused depletion of available number prefixes, often requiring ten-digit local calls and overlay plans ...
The North American Numbering Plan is based on a ten-digit telephone number assigned to each telephone in the telephone network. The number is composed of the three-digit numbering plan area code, a three-digit central office code, and a four-digit station or line number. Certain rules govern the numerical format of each part.
For example, 234 235-5678 is a valid telephone number; with area code 234, central office prefix (exchange) 235, and line number 5678. The number 234 911-5678 is invalid, because the central office code must not be in the form N11. 314 159-2653 is invalid, because the office code must not begin with 1.
Phone support is available for account management and password reset help, Mon-Fri: 8am-12am ET; Sat: 8am-10pm ET. For additional hours of operation for different services visit our support options page for contact info.
Under all-number calling, the number of permissible central office prefixes increased from 540 to potentially 800, but the first two digits of the central office code were still restricted to the range 2 to 9, and the eight combinations that ended in 11 were reserved as special calling codes. [2]
Get answers to your AOL Mail, login, Desktop Gold, AOL app, password and subscription questions. Find the support options to contact customer care by email, chat, or phone number.