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Toll Restriction
Toll restriction or toll denial is a feature offered by telephone companies which allows a line to be so programmed that it is impossible to originate long-distance calls from that line, or to accept charges reversed to the number by other parties. Such lines usually allow calls to be made to no-charge numbers locally and toll-free (under the North American Numbering Plan, area codes 800, 844, 855, 866, 877 and 888), so customers can still make some long-distance calls. Most commonly this restriction is applied at the request of the owner of the premises, who does not wish to be subject to unlimited liability for costly unauthorised calls made by others at the site. Restriction of calls to overseas or premium-rate telephone numbers are common options on some systems, such as voice over IP. Private branch exchange A business telephone system is a multiline telephone system typically used in business environments, encompassing systems ranging in technology from the key telephone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone
A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals that are transmitted via cables and other communication channels to another telephone which reproduces the sound to the receiving user. The term is derived from el, τῆλε (''tēle'', ''far'') and φωνή (''phōnē'', ''voice''), together meaning ''distant voice''. A common short form of the term is ''phone'', which came into use early in the telephone's history. In 1876, Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice at a second device. This instrument was further developed by many others, and became rapidly indispensable in business, government, and in households. The essential elements of a telephone are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Line
A telephone line or telephone circuit (or just line or circuit industrywide) is a single-user circuit on a telephone communication system. It is designed to reproduce speech of a quality that is understandable. It is the physical wire or other signaling medium connecting the user's telephone apparatus to the telecommunications network, and usually also implies a single telephone number for billing purposes reserved for that user. Telephone lines are used to deliver landline telephone service and Digital subscriber line (DSL) phone cable service to the premises. Telephone overhead lines are connected to the public switched telephone network. The voltage at a subscriber's network interface is typically 48 V between the ring and tip wires, with tip near ground and ring at -48 V. In the United States In 1878, the Bell Telephone Company began to use two-wire circuits, called the local loop, from each user's telephone to end offices which performed any necessary electrical swit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long-distance Calling
In telecommunications, a long-distance call (U.S.) or trunk call (also known as a toll call in the U.K. ) is a telephone call made to a location outside a defined local calling area. Long-distance calls are typically charged a higher billing rate than local calls. The term is not necessarily synonymous with placing calls to another telephone area code. Long-distance calls are classified into two categories: national or domestic calls which connect two points within the same country, and international calls which connect two points in different countries. Within the United States there is a further division into long-distance calls within a single state (intrastate) and interstate calls, which are subject to different regulations (counter-intuitively, calls within states are usually more expensive than interstate calls). Not all interstate calls are long-distance calls. Since 1984 there has also been a distinction between intra-local access and transport area (LATA) calls and those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North American Numbering Plan
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. The NANP was originally devised in the 1940s by the AT&T Corporation, American Telephone and Telegraph Company (AT&T) for the Bell System and the independent telephone operators in North America. The goal was to unify the diverse local numbering plans that had been established in the preceding decades and prepare the continent for direct-dialing of calls by customers without the involvement of telephone operators. AT&T continued to administer the numbering plan until the breakup of the Bell System, when administration was delegated to the North American Numbering Plan Administrator (NANPA), a service that has been procured from the private sect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premium-rate Telephone Number
Premium-rate telephone numbers are telephone numbers that charge callers higher price rates for select services, including information and entertainment. A portion of the call fees is paid to the service provider, allowing premium calls to be an additional source of revenue for businesses. Tech support, psychic hotlines, and adult chat lines (e.g. dating and phone sex) are among the most popular kinds of premium-rate phone services. Other services include directory enquiries, weather forecasts, competitions and ratings televoting (especially relating to television shows). Diplomatic services, such as the US Embassy in London or the UK Embassy in Washington, have also charged premium rates for calls from the general public. Premium calls are typically routed like toll-free numbers, and service providers can be located independent of the area code. These telephone numbers are usually allocated based on a national telephone numbering plan that makes them easily distinguis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voice Over IP
Voice over Internet Protocol (VoIP), also called IP telephony, is a method 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 Internet, rather than via the public switched telephone network (PSTN), also known as plain old telephone service (POTS). Overview The steps and principles involved in originating VoIP telephone calls are similar to traditional digital telephony and involve signaling, channel setup, digitization of the analog voice signals, and encoding. Instead of being transmitted over a circuit-switched network, the digital information is packetized and transmission occurs as IP packets over a packet-switched network. They transport media streams using special media delivery proto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Private Branch Exchange
A business telephone system is a multiline telephone system typically used in business environments, encompassing systems ranging in technology from the key telephone system (KTS) to the private branch exchange (PBX). A business telephone system differs from an installation of several telephones with multiple central office (CO) lines in that the CO lines used are directly controllable in key telephone systems from multiple telephone stations, and that such a system often provides additional features related to call handling. Business telephone systems are often broadly classified into key telephone systems, and private branch exchanges, but many hybrid systems exist. A key telephone system was originally distinguished from a private branch exchange in that it did not require an operator or attendant at the switchboard to establish connections between the central office trunks and stations, or between stations. Technologically, private branch exchanges share lineage with centra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
