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North American Numbering Plan Expansion
The expansion of the North American Numbering Plan (NANP) is the anticipated requirement for providing more telephone numbers to accommodate future needs beyond the pool of ten-digit telephone numbers. Ten-digit telephone numbers have been in use in the United States and Canada in long-distance telephone service since the 1950s. An October 2020 analysis estimated that the numbering plan would not be exhausted until after 2050. History In the 1940s, the American Telephone and Telegraph Company (AT&T) devised the first comprehensive continental telephone numbering plan to implement destination routing in Operator Toll Dialing with the goal of speeding the connection times in long-distance telephony. By 1951, this plan became the foundation for Direct Distance Dialing by telephone service subscribers. In the following two decades, the numbering plan became the foundation for the North American Numbering Plan (NANP), a membership organization for North American countries and affili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North American Numbering Plan
The North American Numbering Plan (NANP) is an integrated 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, World Numbering Zone 1 and has the telephone country code, country code ''1''. Some North American countries, most notably Telephone numbers in Mexico, Mexico, do not participate in the NANP. The concepts of the NANP were devised originally during the 1940s by the American Telephone and Telegraph Company (AT&T) for the Bell System and the independent telephone companies in North America in Operator Toll Dialing. The first task was to unify the diverse local telephone numbering plans that had been established during the preceding decades, with the goal to speed call completion times and decrease the costs for long-distance calling, by reducing manual labor by switchboard operators. Eventually, it prepared the continent for direct-dialing of long-distance calls ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code Split
In telecommunications, an area code split is the practice of introducing a new telephone area code by geographically dividing an existing numbering plan area (NPA), and assigning area codes to the resulting divisions, but retaining the existing area code only for one of the divisions. The purpose of this practice is to provide more central office prefixes, and therefore more telephone numbers, in an area with high demand for telecommunication services, and prevent a shortage of telephone numbers. An increasing demand for telephone numbers has existed since the development of automatic telephony in the early 20th century, but was spurred especially since the 1990s, with the proliferation of fax machines, pager systems, mobile telephones, computer modems and, eventually, smart phones. The implementation of an area code split typically involves the establishment of a Class-4 toll switching center for each division of the existing numbering plan area that receive a new area code. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Call
In telephony, the term local call has the following meanings: # Any call using a single switching center; that is, not traveling to another telephone network; # A call made within a local calling area as defined by the local exchange carrier; # Any call for which an additional charge, ''i.e.'', toll charge, is not billed to the calling or called party, or (depending on the country) for which this charge is reduced because it is a short-distance call (e.g. within a town or local metropolitan area). Typically, local calls have shorter numbers than long-distance calls, as the area code may not be required. However, this is not true in parts of the United States and Canada that are subject to overlay plans or many countries in Europe that require closed dialing plans. Toll free A toll-free telephone number or freephone number is a telephone number that is billed for all arriving calls. For the calling party, a call to a toll-free number is free of charge, unless air-charges appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Numbering Plan
A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, reachable by a system of destination code routing. Telephone numbering plans are defined world-wide, as well as within each of the administrative regions of the public switched telephone network (PSTN), and in private telephone networks. In public numbering systems, geographic location typically plays a role in the sequence of numbers assigned to each telephone subscriber. Many numbering plan administrators subdivide their territory of service into geographic regions designated by a prefix, often called an area code or city code, which is a set of digits forming the most-significant part of the dialing sequence to reach a telephone subscriber. Within such regions designated by area codes, locally unique telephone number are assigned based on lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Number Pooling
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. In the United States it replaced the practice of allocating all 10,000 numbers of a central office prefix at a time. Under number pooling, the entire prefix is assigned to a rate center, to be shared among all providers delivering services in that rate center. Number pooling reduced the quantity of unused telephone numbers in markets which have been fragmented between multiple service providers, avoided central office prefix exhaustion in high growth areas, and extended the lifetime of the North American telephone numbering plan without structure changes of telephone numbers. Telephone number pooling was first tested for area code 847 in Illinois in June 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rate Center
In the North American Numbering Plan, a rate center (rate centre in Canada) is a geographically-specified area used for determining mileage and/or usage dependent rates in the public switched telephone network. Unlike a wire center (which is the actual physical telephone exchange building), a rate center is a regulatory construct created primarily for billing purposes. Each rate center is associated with: * a geographical place name (city, province/state) * a nominal physical location (V and H co-ordinates) for distance calculations for billing purposes * one or more prefixes, in the form +1-NPA-NXX, which each identify a block of ten thousand directory numbers * a specified local calling area, identified as a list of other individual rate centers to which local or flat-rate landline calling is provided A rate center may contain one or multiple physical wire centers; conversely, it may merely be a legal fiction retained for billing purposes with its actual subscribers served fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ten-digit Dialing
Ten-digit dialing is a telephone dialing procedure in the countries and territories of the North American Numbering Plan (NANP). It is the practice of including the area code of a telephone number when Dialling (telephony), dialing to initiate a telephone call. When necessary, the ten-digit number may be prefixed with the trunk code ''1'', which is referred to as ''1+10-digit dialing'' or ''national format''. History The implementation and expansion of the North American Numbering Plan between 1947 and 1992 preserved a long-standing practice in the United States and Canada that callers should only need to dial the local seven-digit telephone number when placing a call within the caller's exchange area or within the home numbering plan area (NPA). In seven-digit dialing, callers dial the three-digit central office code and the four-digit station number of the destination telephone if it resides in the same numbering plan area. Dialing of an area code before the telephone number, ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seven-digit Dialing
Seven-digit dialing is a telephone dialing procedure customary in some territories of the North American Numbering Plan (NANP) for dialing telephone numbers in the same numbering plan area (NPA). NANP telephone numbers consist of ten digits, of which the leading three are the area code. In seven-digit dialing it is not necessary to dial the area code. The procedure is also sometimes known as ''local format'' or ''network format''. History Originally, telephone exchanges consisted of manual switchboards operated by switchboard operators. Telephone numbers had typically two to four digits, depending on the size of the community. As the number of subscribers grew, multiple exchanges served individual neighborhoods of large cities. Multiple exchanges were identified by a central office name and typically four digits, such as "Pennsylvania 5000". A rural telephone number, often party line, had often up to four digits and a letter or letter and digits to indicate which of the multiple p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overlay Plan
In telecommunications, an area code overlay complex is a telephone numbering plan that assigns multiple area codes to the same geographic numbering plan area (NPA). Area code overlays are implemented in territories of the North American Numbering Plan (NANP) to mitigate exhaustion of central office codes in growth areas. The method has been in use since 1992, and has been the exclusive method of area code relief since 2007. History From the inception of the North American Numbering Plan in 1947 until 1992, the only method of introducing new area codes was the area code split. It divided an existing numbering plan area (NPA) into multiple regions, one of which retained the existing area code. The other parts were each assigned a new NPA code. The retaining area was usually the historically more established or developed place, and required no numbering changes. It gained numbering capacity by acquiring the central office codes of the other areas, because those were delegated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Switching System
In telecommunications, an electronic switching system (ESS) is a telephone switch that uses solid-state electronics, such as digital electronics and computerized common control, to interconnect telephone circuits for the purpose of establishing telephone calls. The generations of telephone switches before the advent of electronic switching in the 1950s used purely electro-mechanical relay systems and analog voice paths. These early machines typically utilized the step-by-step technique. The first generation of electronic switching systems in the 1960s were not entirely digital in nature, but used reed relay-operated metallic paths or crossbar switches operated by stored program control (SPC) systems. First announced in 1955, the first customer trial installation of an all-electronic central office commenced in Morris, Illinois in November 1960 by Bell Laboratories. The first large-scale electronic switching system was the Number One Electronic Switching System (1ESS) of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Number
A telephone number is the address of a Telecommunications, telecommunication endpoint, such as a telephone, in a telephone network, such as the public switched telephone network (PSTN). A telephone number typically consists of a Number, sequence of digits, but historically letters were also used in connection with telephone exchange names. Telephone numbers facilitate the switching and routing of telephone call, calls using a system of destination code routing. Telephone numbers are entered or dialed by a calling party on the originating telephone set, which transmits the sequence of digits in the process of signaling to a telephone exchange. The exchange completes the call either to another locally connected subscriber or via the PSTN to the called party. Telephone numbers are assigned within the framework of a national or regional telephone numbering plan to subscribers by telephone service operators, which may be commercial entities, state-controlled administrations, or ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interchangeable NPA Code
In the North American Numbering Plan (NANP), interchangeable NPA and central office codes constituted a change in numbering plan design and policy, to mitigate exhaustion of the numbering resources of the ten-digit telephone numbers used in the closed numbering plan of the NANP. Interchangeable numbering plan area (NPA) codes and central office codes are codes that permit any of the ten numerals in the middle position of the area code and the central office code, which both are three-digit numbers.AT&T Network Planning Division, ''Notes on the Network'', Section 2 (1980) This change in numbering format was implemented first for central office codes by 1973, which eliminated the restriction in the middle digit (''2'' to ''9'') to also permit ''0'' and ''1''. The middle position of the area code could only be ''0'' and ''1''. In 1995, this restriction for area codes was lifted as well, creating interchangeable NPA codes. History and background The ten-digit telephone numbers of the N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
