Search results
Results from the WOW.Com Content Network
Country codes are defined by the International Telecommunication Union (ITU) in ITU-T standards E.123 and E.164. The prefixes enable international direct dialing (IDD). Country codes constitute the international telephone numbering plan. They are used only when dialing a telephone number in a country or world region other than the caller's.
This is a list of international dialing prefixes used in various countries for direct dialing of international telephone calls.These prefixes are typically required only when dialling from a landline, while in GSM-compliant mobile phone (cell phone) systems, only the symbol + before the country code may be used [citation needed] irrespective of where the telephone is used at that moment; the ...
Signalling System No. 7 ( SS7) is a set of telephony signaling protocols developed in the 1970s, which is used to set up and tear down telephone calls in most parts of the world-wide public switched telephone network (PSTN). The protocol also performs number translation, local number portability, prepaid billing, Short Message Service (SMS ...
When dialing a telephone number, the area code may have to be preceded by a trunk prefix or national access code for domestic calls, and for international calls by the international access code and country code. Area codes are often quoted by including the national access code. For example, a number in London may be listed as 020 7946 0321.
1. International access. 011. List of dialing codes. 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 telephone country code 1. Some North American countries, most notably ...
An "international call prefix", "international dial-out code" or "international direct dial code" (IDD code) is a trunk prefix that indicates an international phone call. In the dialling sequence, the prefix precedes the country calling code (and, further, the carrier code, if any, and the destination telephone number ).
AT&T. AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. [4] It is the world's third-largest telecommunications company by revenue and the second-largest wireless carrier in the United States. [5] As of 2023, AT&T was ranked 13th on the Fortune 500 rankings of the ...
Recommendation ITU-T E.164. E.164 is an international standard ( ITU-T Recommendation), titled The international public telecommunication numbering plan, that defines a numbering plan for the worldwide public switched telephone network (PSTN) and some other data networks . E.164 defines a general format for international telephone numbers.