Telephone number

phone numbertelephone numbersphone numbers
A telephone number is a sequence of digits assigned to a fixed-line telephone subscriber station connected to a telephone line or to a wireless electronic telephony device, such as a radio telephone or a mobile telephone, or to other devices for data transmission via the public switched telephone network (PSTN) or other public and private networks. A telephone number serves as an address for switching telephone 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.

North American Numbering Plan

Area codeArea codesArea code(s)
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 plan area. The telephone number consists of a three-digit central office 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). For international call routing, the NANP has been assigned the international calling code 1 by the International Telecommunications Union (ITU).

Voice over IP

VoIPvoice over Internet Protocolvoice-over-IP
Voice over Internet Protocol (VoIP), also called IP telephony, is a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet telephony, broadband telephony, and broadband phone service specifically refer to the provisioning of communications services (voice, fax, SMS, voice-messaging) over the public Internet, rather than via the public switched telephone network (PSTN).

Telephone call

callphone callphone calls
Preceding, during, and after a traditional telephone call is placed, certain tones signify the progress and status of the telephone call: Cell phones generally do not use dial tones, because the technology used to transmit the dialed number is different from a landline. Unsolicited telephone calls are a modern nuisance. Common kinds of unwanted calls include prank calls, telemarketing calls, and obscene phone calls. Caller ID provides some protection against unwanted calls, but can still be turned off by the calling party.

Telephone exchange

exchangescentral officeexchange
Instead, the RT is connected digitally to equipment in the telephone switch. This reduces the total amount of equipment required. Switches are used in both local central offices and in long distance centers. There are two major types in the Public switched telephone network (PSTN), the Class 4 telephone switches designed for toll or switch-to-switch connections, and the Class 5 telephone switches or subscriber switches, which manage connections from subscriber telephones. Since the 1990s, hybrid Class 4/5 switching systems that serve both functions have become common. Another element of the telephone network is time and timing.

Signalling System No. 7

SS7SS7 NetworkCCS7
Signaling System No. 7 (SS7) is a set of telephony signaling protocols developed in 1975, which is used to set up and tear down most of the world's public switched telephone network (PSTN) telephone calls. It also performs number translation, local number portability, prepaid billing, Short Message Service (SMS), and other mass market services. In North America it is often referred to as CCSS7, abbreviated for Common Channel Signaling System 7. In the United Kingdom, it is called C7 (CCITT number 7), number 7 and CCIS7 (Common Channel Interoffice Signaling 7). In Germany, it is often called ZZK-7 (Zentraler ZeichengabeKanal Nummer 7).

Telephone

phonetelephonesLocal Telephone Service
This gave rise to landline telephone service in which each telephone is connected by a pair of dedicated wires to a local central office switching system, which developed into fully automated systems starting in the early 1900s, and eventually into a worldwide public switched telephone network. For greater mobility, various radio systems were developed for transmission between mobile stations on ships and automobiles in the mid-20th century. Hand-held mobile phones were introduced for personal service starting in 1973. In later decades their analog cellular system evolved into digital networks with greater capability and lower cost.

9-1-1

911911 call9-1-1 call
With regard to mobile phones, the rules require carriers to connect 9-1-1 calls from any mobile phone, regardless of whether that phone is currently active. Similar rules for inactive telephones apply in Canada. When a cellular phone is deactivated, the phone number is often recycled to a new user, or to a new phone for the same user. The deactivated cell phone will still complete a 9-1-1 call (if it has battery power) but the 9-1-1 dispatcher will see a specialized number indicating the cell phone has been deactivated. It is usually represented with an area code of (911)-xxx-xxxx. If the call is disconnected, the 9-1-1 dispatcher will not be able to connect to the original caller.

VoIP phone

IP PhoneIP PhonesEthernet-based phone
A VoIP phone or IP phone uses voice over IP technologies for placing and transmitting telephone calls over an IP network, such as the Internet, instead of the traditional public switched telephone network (PSTN). Digital IP-based telephone service uses control protocols such as the Session Initiation Protocol (SIP), Skinny Client Control Protocol (SCCP) or various other proprietary protocols. VoIP phones can be simple software-based softphones or purpose-built hardware devices that appear much like an ordinary telephone or a cordless phone. Traditional PSTN phones are used as VoIP phones with analog telephone adapters (ATA).

Overlay plan

overlayoverlaidoverlay area code
It was originally established as an area code specifically for cell phones and pagers in New York City, but soon after, the FCC said area codes going forth could not be service-specific, but they allowed 917 to remain as such. However, 917 is being used for landlines in New York City on a limited basis. List of area code overlays. Interexchange carrier. Telephone exchange. Telephone numbering plan. Exhaust date.

Toll-free telephone number

toll-freetoll-free number800 number
Countries around the world use various dialing prefixes to denote toll-free services in their telephone networks. Toll-free numbers in the North American Numbering Plan (NANP) are commonly called "800 numbers" after the original area code which was used to dial them. They include the area code 800 (since January 1, 1966), 888 (since March 1, 1996), 877 (since April 4, 1998), 866 (since July 29, 2000), 855 (since October 9, 2010), 844 (since December 7, 2013), and 833 (since April 22, 2017). Area codes reserved for future expansion include 822, 880 through 887, and 889. The original Wide Area Telephone Service is obsolete.

Landline

fixed linefixed-lineland line
That same year, 2008, about 77% of adults owned a mobile phone. In the year 2013, 91% of adults in the United States owned a mobile phone. Almost 60% of those with a mobile had a smartphone. A National Health Interview Survey of 19,956 households by the Centers for Disease Control and Prevention released May 4, 2017 showed only 45.9 percent of U.S. households still had landlines, while 50.8 percent had only cell phones. Over 39 percent had both. In Canada, more than one in five of households use cell phones as their only source for telephone service. In 2013, statistics showed that 21% of households claimed to only use cellular phones.

Caller ID

caller line identificationCLIcall display
In the typical telephony environment, a PBX connects to the local service provider through Primary Rate Interface (PRI) trunks. Generally, although not absolutely, the service provider simply passes whatever calling line ID appears on those PRI access trunks transparently across the Public Switched Telephone Network (PSTN). This opens up the opportunity for the PBX administrator to program whatever number they choose in their external phone number fields. Some IP phone services (ITSPs, or Internet Telephony Service Providers) support PSTN gateway installations throughout the world. These gateways egress calls to the local calling area, thus avoiding long distance toll charges.

Directory assistance

directory enquiries118 5001-800-555-1212
Example: The caller is looking for a listing in Los Angeles, CA (area code 213) and dials 213-555-1212. In this case Verizon bills the call. 4) 00 and ask for the international directory assistance operator. AT&T provides International Directory Assistance calls. See www.consumer.att.com/global/english/country_codes.html for additional information and country and city codes. 555 (telephone number). Telephone directory.

Telecommunication

telecommunicationscommunicationstelecom
As of 2015, the landline telephones in most residential homes are analog—that is, the speaker's voice directly determines the signal's voltage. Although short-distance calls may be handled from end-to-end as analog signals, increasingly telephone service providers are transparently converting the signals to digital signals for transmission. The advantage of this is that digitized voice data can travel side-by-side with data from the Internet and can be perfectly reproduced in long distance communication (as opposed to analog signals that are inevitably impacted by noise). Mobile phones have had a significant impact on telephone networks.

SMS

short message servicetext messagetext messages
According to one market research report, as of 2014, the global SMS messaging business was estimated to be worth over $100 billion, accounting for almost 50 percent of all the revenue generated by mobile messaging. Adding text messaging functionality to mobile devices began in the early 1980s. The first action plan of the CEPT Group GSM was approved in December 1982, requesting that "The services and facilities offered in the public switched telephone networks and public data networks ... should be available in the mobile system." This plan included the exchange of text messages either directly between mobile stations, or transmitted via message handling systems in use at that time.

Telephone tapping

wiretapwiretappingwiretaps
However the government can tap mobile phones with the cooperation of the phone company. It is also possible for organizations with the correct technical equipment to monitor mobile phone communications and decrypt the audio. To the mobile phones in its vicinity, a device called an "IMSI-catcher" pretends to be a legitimate base station of the mobile phone network, thus subjecting the communication between the phone and the network to a man-in-the-middle attack. This is possible because, while the mobile phone has to authenticate itself to the mobile telephone network, the network does not authenticate itself to the phone.

Emergency telephone number

emergency callemergency numberemergency calls
In many countries the public switched telephone network has a single emergency telephone number (sometimes known as the universal emergency telephone number or the emergency services number) that allows a caller to contact local emergency services for assistance. The emergency number differs from country to country; it is typically a three-digit number so that it can be easily remembered and dialed quickly. Some countries have a different emergency number for each of the different emergency services; these often differ only by the last digit. See List of emergency telephone numbers. The emergency telephone number is a special case in the country's telephone number plan.

Vertical service code

calling featureservice featureCLASS
Local Area Signalling Services (LASS) and Custom Calling Feature Control Codes: de:Vermittlungstechnische Leistungsmerkmale (öffentliche Netze) Mobile dial code. Pat Fleet – Prompt voice for most U.S. AT&T implementations of VSC features. Public switched telephone network. Short code. Signalling System 7.

UK telephone code misconceptions

common misconceptionerroneous UK telephone codesmisquoted
Telephone numbering plan.

Nortel

Nortel NetworksNorthern ElectricNorthern Telecom
It served both general businesses and communications carriers (landline telephone, mobile phone, and cable TV carriers). Technologies included telephonic (voice) equipment, fiber optics, local wireless, and multimedia. Past products included: In 2016 the Canadian Broadcasting Corporation, reported that lawyers and accountants received $2.5 billion from Nortel's estate In September 1991, Julian Assange of WikiLeaks was discovered in the act of hacking into the Melbourne master terminal of Nortel. In 2004, it was discovered that crackers (malicious hackers) gained almost complete access to Nortel's systems.

Wireless home phone

A wireless home phone service is a service that allows a regular wired telephone to connect to a cellular network, as if it were a mobile phone. It is an example of a wireless last mile connection to the public switched telephone network, also known as a wireless local loop. A small device, about the size of a home wireless router, contains the necessary electronics which allow plain old telephone service to be provided to one or two telephone jacks on the back of the unit, as well as having a small radio antenna and a transceiver for the wireless side of the connection. LED indicator lights on the front typically show signal strength and voicemail messages waiting.

Index of telephone-related articles

Plain old telephone service (POTS). Private branch exchange. Public switched telephone network. Satellite phone. Sidetone. Telecommunications. Telephone. Telephone call. Telephone directory. Telephone exchange. Telephone line. Telephone newspaper. Telephone number. Telephone switchboard. Telephone tapping. Telephony. Thomas Edison. Timeline of the telephone. Tip and ring (Wiring terminology). Toll-free telephone number.

Integrated Services Digital Network

ISDN ISDNISDN30
ISDN is also used as a smart-network technology intended to add new services to the public switched telephone network (PSTN) by giving users direct access to end-to-end circuit-switched digital services and as a backup or failsafe circuit solution for critical use data circuits. ISDN is used heavily by the broadcast industry as a reliable way of switching low-latency, high-quality, long-distance audio circuits.

867-5309/Jenny

867-5309867-5309 (Jenny)867-5309 and asking for Jenny
In 2013, the number was still ringing up fifty misdialled calls daily for Florida realtor Carrie Routt in area code 850. Phoenix, Arizona-based professional services referral company MyGuy Referrals also use the number, in area code 602. Fort Collins, Colorado restaurant, Totally 80's Pizza, uses this number as part of its 1980s theme, in area code 970. Fictitious telephone number. Denial-of-service attack#Telephony denial-of-service. List of Billboard Mainstream Rock number-one songs of the 1980s.