Continuous redial, busy number redial, or repeat dial [1] is a vertical service code (calling feature) that allows callers to automatically redial a busy telephone number until a connection is made. It was introduced in 1992 as Repeat Dialing, [1] and is activated by dialing a combination of special characters and numbers after hanging up following a call to a busy line. It will run for a set period of time (such as 30 minutes) and can be deactivated by entering either the same set of numbers or a different set. The North American Numbering Plan assigned *66 to activate continuous redial and *86 to deactivate it.
A hotline is a point-to-point communications link in which a call is automatically directed to the preselected destination without any additional action by the user when the end instrument goes off-hook. An example would be a phone that automatically connects to emergency services on picking up the receiver. Therefore, dedicated hotline phones do not need a rotary dial or keypad. A hotline can also be called an automatic signaling, ringdown, or off-hook service.
Most public switched telephone networks have a single emergency telephone 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.
A dial tone is a telephony signal sent by a telephone exchange or private branch exchange (PBX) to a terminating device, such as a telephone, when an off-hook condition is detected. It indicates that the exchange is working and is ready to initiate a telephone call. The tone stops when the first dialed digit is recognized. If no digits are forthcoming, the partial dial procedure is invoked, often eliciting a special information tone and an intercept message, followed by the off-hook tone, requiring the caller to hang up and redial.
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 international calling code 1. Some North American countries, most notably Mexico, do not participate in the NANP.
A telephone call is a connection over a telephone network between the called party and the calling party.
A toll-free telephone number or freephone number is a telephone number that is billed for all arriving calls instead of incurring charges to the originating telephone subscriber. For the calling party, a call to a toll-free number from a landline is free of charge.
Call waiting is a telephone service where a subscriber can accept a second incoming telephone call by placing an in-progress call on hold—and may also switch between calls. With some providers it can be combined with additional features such as conferencing, call forwarding, and caller ID. Call waiting is intended to alleviate the need to have more than one telephone line or number for voice communications.
Call forwarding, or call diversion, is a telephony feature of all telephone switching systems which redirects a telephone call to another destination, which may be, for example, a mobile or another mobile or another telephone number where the desired called party is available. Call forwarding was invented by Ernest J. Bonanno. In North America, the forwarded line usually rings once to remind the customer using call forwarding that the call is being redirected. More consistently, the forwarded line indicates its condition by stutter dial tone. Call forwarding typically can redirect incoming calls to any other domestic telephone number, but the owner of the forwarded line must pay any toll charges for forwarded calls. Call forwarding is often enabled by dialing *72 followed by the telephone number to which calls should be forwarded. Once someone answers, call forwarding is in effect. If no one answers or the line is busy, the dialing sequence must be repeated to effect call forwarding. Call forwarding is disabled by dialing *73. This feature requires a subscription from the telephone company. Also available in some areas is Remote Access to call forwarding, which permit the control over call forwarding from telephones other than the subscriber's telephone. VOIP and cable telephone systems also allow call forwarding to be set up and directed via their web portals.
Subscriber trunk dialling (STD), also known as subscriber toll dialing, is a telephone numbering plan feature and telecommunications technology for the dialling of trunk calls by telephone subscribers without the assistance from switchboard operators.
111 is the emergency telephone number in New Zealand. It was first implemented in Masterton and Carterton on 29 September 1958, and was progressively rolled out nationwide with the last exchanges converting in 1988.
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 in each of the administrative regions of the public switched telephone network (PSTN) and in private telephone networks.
Last-call return, automatic recall, or camp-on, is a telecommunication feature offered by telephony service providers to subscribers to provide the subscriber with the telephone number, and sometimes the time, of the last caller. The service may also offer the facility to place a call to the calling party.
Telephone numbers in the United Kingdom are administered by the Office of Communications (Ofcom). For this purpose, Ofcom established a telephone numbering plan, known as the National Telephone Numbering Plan, which is the system for assigning telephone numbers to subscriber stations.
In telephony, a message-waiting indicator (MWI) is a Telcordia Technologies term for an FSK-based telephone calling feature that illuminates an LED on selected telephones to notify a telephone user of waiting voicemail messages on most North American public telephone networks and PBXs.
Numbers on the Irish telephone numbering plan are regulated and assigned to operators by ComReg.
The reorder tone, also known as the fast busy tone, or the congestion tone, or all trunks busy (ATB) tone is an audible call progress tone in the public switched telephone network (PSTN) that is returned to a calling party to indicate that the call cannot be processed through the network.
AT&T Merlin is a corporate telephone system by American Telephone and Telegraph (AT&T) that was introduced in late 1983, when it was branded American Bell Merlin. After the breakup of AT&T in 1984, it was rebranded and later also supplied by Lucent and Avaya.
A telephone number is a sequence of digits assigned to a landline 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.
In telecommunication, a personal communications service is defined by the Alliance for Telecommunications Industry Solutions (ATIS) as "a set of capabilities that allows some combination of personal mobility, terminal mobility, and service profile management".
The push-button telephone is a telephone that has buttons or keys for dialing a telephone number, in contrast to having a rotary dial as in earlier telephone instruments.
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This article incorporates public domain material from the General Services Administration document: "Federal Standard 1037C".
