DMS-250
The DMS-100 is a member of the Digital Multiplex System (DMS) product line of telephone exchange switches manufactured by Northern Telecom. Designed during the 1970s and released in 1979, it can control 100,000 telephone lines. The purpose of the DMS-100 Switch is to provide local service and connections to the PSTN public telephone network. It is designed to deliver services over subscribers' telephone lines and trunks. It provides plain old telephone service (POTS), mobility management for cellular phone systems, sophisticated business services such as automatic call distribution (ACD), Integrated Services Digital Network (ISDN), and Meridian Digital Centrex (MDC), formerly called Integrated Business Network (IBN). It also provides Intelligent Network functions (AIN, CS1-R, ETSI INAP). It is used in countries throughout the world. There are also DMS-200 and DMS-250 variants for tandem switches. Much of the hardware used in the DMS-100, with the possible exception of the line ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Digital Multiplex System
Digital Multiplex System (DMS) is the name shared among several different telephony product lines from Nortel Networks for wireline and wireless operators. Among them are the DMS-1 (originally named the DMS-256) Rural/Urban digital loop carrier, the DMS-10 telephone switch, the DMS SuperNode family of telephone switches (DMS-100, DMS-200, DMS-250, DMS-300, DMS-500, DMS-GSP, DMS-MSC, DMS-MTX), and the S/DMS optical transmission system. Exploratory development on the technology began at Northern Telecom's Bell Northern Research Labs in Ottawa, Ontario in 1971. The first Class 5 switch, the DMS-10, began service on 21 October 1977 in Fort White, Florida and the first toll switch (Class 4), the DMS-200, entered service in 1979 in Ottawa. The DMS-10 was the first commercially successful Class 5 digital switch in the North American market and had a profound impact on the industry. Of the numerous digital switching products introduced in the North American telephone market in the la ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Class-4 Telephone Switch
A class-4, or tandem, telephone switch is a U.S. telephone company central office telephone exchange used to interconnect local exchange carrier offices for long distance communications in the public switched telephone network. A class-4 switch does not connect directly to telephones; instead, it connects to other class-4 switches and to class-5 telephone switches. The telephones of service subscribers are wired to class-5 switches. When a call is placed to a telephone that is not on the same class-5 switch as the originating subscriber, the call may be routed through one or more class-4 switches to reach its destination. Etymology ''Tandem'' derives from the Latin adverb ''tandem'' meaning ''at length'', and is used in English to mean a group of two people or machines working together, usually in series. A tandem switch is used to interconnect other switches via trunks. Thus, tandem switches are always part of a series of switches and lines that connect telephone callers to ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Typical Northern Telecom DMS100 Telephone Central Office Installation '', an American Comedy Central television series
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Typical may refer to: * ''Typical'' (album), Peter Hammill * "Typical" (song), song by MuteMath *"Typical", song by Frazier Chorus from ''Sue'', 1987 *''Typical'', story collection by Padgett Powell, 1991 See also *''Typical Rick ''Typical Rick'' is an American television series produced by Comedy Central, created by Nicholaus Goossen and Nick Swardson. Comedy Central declined to renew the series for a third season. Cast * Nick Swardson as Gary * Simon Rex as Rick * Mega ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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68030
The Motorola 68030 ("''sixty-eight-oh-thirty''") is a 32-bit microprocessor in the Motorola 68000 family. It was released in 1987. The 68030 was the successor to the Motorola 68020, and was followed by the Motorola 68040. In keeping with general Motorola naming, this CPU is often referred to as the 030 (pronounced ''oh-three-oh'' or ''oh-thirty''). The 68030 is essentially a 68020 with a memory management unit (MMU) and instruction and data caches of 256 bytes each. It added a burst mode (computing), burst mode for the caches, where four longwords can be loaded into the cache in a single operation. The MMU was mostly compatible with the external Motorola 68851, 68851 that would be used with the 68020, but being internal allowed it to access memory one cycle faster than a 68020/68851 combo. The 68030 did not include a built-in floating-point unit (FPU), and was generally used with the Motorola 68881, 68881 and the faster Motorola 68882, 68882. The addition of the FPU was a major d ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Key Telephone System
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]   |
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Data Link
A data link is the means of connecting one location to another for the purpose of transmitting and receiving digital information (data communication). It can also refer to a set of electronics assemblies, consisting of a transmitter and a receiver (two pieces of data terminal equipment) and the interconnecting data telecommunication circuit. These are governed by a link protocol enabling digital data to be transferred from a data source to a data sink. Types There are at least three types of basic data-link configurations that can be conceived of and used: * Simplex communications, most commonly meaning all communications in one direction only. * Half-duplex communications, meaning communications in both directions, but not both ways simultaneously. * Duplex communications, communications in both directions simultaneously. Aviation In civil aviation, a data-link system (known as Controller Pilot Data Link Communications) is used to send information between aircraft and air tr ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Northern Telecom DMS-100 Line Card Drawer Showing Line Cards
Northern may refer to the following: Geography * North, a point in direction * Northern Europe, the northern part or region of Europe * Northern Highland, a region of Wisconsin, United States * Northern Province, Sri Lanka * Northern Range, a range of hills in Trinidad Schools * Northern Collegiate Institute and Vocational School (NCIVS), a school in Sarnia, Canada * Northern Secondary School, Toronto, Canada * Northern Secondary School (Sturgeon Falls), Ontario, Canada * Northern University (other), various institutions * Northern Guilford High School, a public high school in Greensboro, North Carolina Companies * Arriva Rail North, a former train operating company in northern England * Northern Bank, commercial bank in Northern Ireland * Northern Foods, based in Leeds, England * Northern Pictures, an Australian-based television production company * Northern Rail, a former train operating company in northern England * Northern Railway of Canada, a defunct railway in On ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ground Start
{{refimprove, date=January 2008 In telephony, ground start is a method of signaling from a terminal of a subscriber local loop to a telephone exchange, where one side of a cable pair is temporarily grounded to request dial tone. Most middle 20th-century American payphones used coin-first ground start lines, with the starting ground connection provided by the coin itself, bridging a set of contacts as it passes through the coin chute. Ground start trunk Telephone companies typically provide two types of dial tone switched circuits – ground start and loop start. Private branch exchanges (PBX) work best on ground start trunks because those trunks can give them an on hook signal allowing for timely clearing. Normal single line telephones and key systems typically work on loop start lines. On loop start lines the PBX and central office may inadvertently seize the line simultaneously, a condition called ''glare'', resulting in call collision since neither gets the expected response ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Loop Start
Loop start is a telecommunications supervisory protocol between a central office or private branch exchange (PBX) and a subscriber telephone or other terminal for the purpose of starting and terminating a telephone call. It is the simplest of the telephone signaling systems, and uses the presence or absence of loop current to indicate the off-hook and on-hook loop states, respectively. It is used primarily for subscriber line signaling. An extension of the protocol that adds disconnect supervision is often called kewlstart. Protocol operation When the telephone is ''on-hook'', the potential of the ring conductor of the local loop is held at a nominal level of -48V DC with respect to the tip conductor, provided by the telephone exchange or a foreign exchange station (FXS) interface. When the terminal initiates use of the line, it causes current to flow by closing the loop, and this signals the exchange to provide dial tone on the line and to expect dial signals, in form of DTMF digi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Caller-id
Caller identification (Caller ID) is a telephone service, available in analog and digital telephone systems, including voice over IP (VoIP), that transmits a caller's telephone number to the called party's telephone equipment when the call is being set up. The caller ID service may include the transmission of a name associated with the calling telephone number, in a service called Calling Name Presentation (CNAM). The service was first defined in 1993 in International Telecommunication Union—Telecommunication Standardization Sector (ITU-T) Recommendation Q.731.3. The information received from the service is displayed on a telephone display screen, on a separately attached device, or on other displays, such as cable television sets when telephone and television service is provided by the same vendor. Value to society includes use by suicide-prevention hot lines and enabling businesses "like pizza restaurants and florists" to quickly have confidence in telephoned orders. The ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Codec
A codec is a device or computer program that encodes or decodes a data stream or signal. ''Codec'' is a portmanteau of coder/decoder. In electronic communications, an endec is a device that acts as both an encoder and a decoder on a signal or data stream, and hence is a type of codec. ''Endec'' is a portmanteau of encoder/decoder. A coder or encoder encodes a data stream or a signal for transmission or storage, possibly in encrypted form, and the decoder function reverses the encoding for playback or editing. Codecs are used in videoconferencing, streaming media, and video editing applications. History In the mid-20th century, a codec was a device that coded analog signals into digital form using pulse-code modulation (PCM). Later, the name was also applied to software for converting between digital signal formats, including companding functions. Examples An audio codec converts analog audio signals into digital signals for transmission or encodes them for storage. A receiv ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Line Card
A line card or digital line card is a modular electronic circuit designed to fit on a separate printed circuit board (PCB) and interface with a telecommunications access network. A line card typically interfaces the twisted pair cable of a plain old telephone service (POTS) local loop to the public switched telephone network (PSTN). Telephone line cards perform multiple tasks, such as analog-to-digital and digital-to-analog conversion of voice, off-hook detection, ring supervision, line integrity tests, and other BORSCHT functions. In some telephone exchange designs, the line cards generate ringing current and decode DTMF signals. The line card in a subscriber loop carrier is called a subscriber line interface card (SLIC). A line card can terminate a line supporting voice POTS service, ISDN service, DSL service, or proprietary ones. Some line cards are capable of terminating more than one type of service. Since an access network element is usually intended to interface many ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |