|
DATU (album)
Direct Access Test Units (DATUs) are special PSTN phone numbers that terminate at the central office switch in a telephone company's local exchange that provide switchmen and telco technicians with a circuit for testing lines in various ways. Among the many things a DATU can do are: * Make certain electrical connections, such as shorting a line's tip to ring, tip to ground, or ring to ground. * Play certain tones on the line (high tone, low tone) to test the line's audio circuit. * Monitor the audio circuit on the line if it is in use (though this only provides a scrambled rendition of the line's audio circuit for privacy and security reasons). * Create and modify certain variables such as counters and timers on the CO switch, as well as adding and modifying exchanges. * Remove a line from permanent signal holding state. DATU's are primarily non-published numbers, though they usually have the phone number XXX-9935 (where XXX represents the local exchange). They are password prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSTN
The public switched telephone network (PSTN) provides infrastructure and services for public telecommunication. The PSTN is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local telephony operators. These consist of telephone lines, fiber optic cables, microwave transmission links, cellular networks, communications satellites, and undersea telephone cables, all interconnected by switching centers which allow most telephones to communicate with each other. Originally a network of fixed-line analog telephone systems, the PSTN is now almost entirely digital in its core network and includes mobile and other networks, as well as fixed telephones. The technical operation of the PSTN adheres to the standards created by the ITU-T. These standards allow different networks in different countries to interconnect seamlessly. The E.163 and E.164 standards provide a single global address space for telephone numbers. The combinat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Exchange
A telephone exchange, telephone switch, or central office is a telecommunications system used in the public switched telephone network (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers. In historical perspective, telecommunication terms have been used with different semantics over time. The term ''telephone exchange'' is often used synonymously with ''central office'', a Bell System term. Often, a ''central office'' is defined as a building used to house the inside plant equipment of potentially several telephone exchanges, each serving a certain geographical area. Such an area has also been referred to as the exchange or exchange area. In North America, a central office location may also be identified as a ''wire center'', designating a facility to which a telephone is connected and obtains dial tone. For business and billing purposes, telecommunication carriers defi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Switch
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of switch is an electromechanical device consisting of one or more sets of movable electrical contacts connected to external circuits. When a pair of contacts is touching current can pass between them, while when the contacts are separated no current can flow. Switches are made in many different configurations; they may have multiple sets of contacts controlled by the same knob or actuator, and the contacts may operate simultaneously, sequentially, or alternately. A switch may be operated manually, for example, a light switch or a keyboard button, or may function as a sensing element to sense the position of a machine part, liquid level, pressure, or temperature, such as a thermostat. Many specialized forms exist, such as the toggle switch, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permanent Signal
Permanent signal (PS) in American telephony terminology, or permanent loop in British usage, is a condition in which a POTS line is off-hook without connection for an extended period of time.Telcordia Technologies, GR-505-CORE Issue 2, December 2005, ''Call Processing'', Section 4.5.2 This is indicated in modern switches by the silent termination after the off-hook tone times out and the telephone exchange computer puts the telephone line on its ''High & Wet list'' or ''Wetlist''. In older switches, however, a Permanent Signal Holding Trunk (PSHT) would play either an off-hook tone (''howler tone'') or a 480/500 Hz high tone (which would subsequently bleed into adjacent lines via crosstalk). Off-hook tone is a tone of increasing intensity that is intended to alert telephone users to the fact that the receiver has been left off the hook without being connected in a call. Permanent signal can also describe the state of a trunk that is seized but has not been dialed upon, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Default Password
Where a device needs a username and/or password to log in, a default password is usually provided that allows the device to be accessed during its initial setup, or after resetting to factory defaults. Manufacturers of such equipment typically use a simple password, such as ''admin'' or ''password'' on all equipment they ship, in the expectation that users will change the password during configuration. The default username and password is usually found in the instruction manual (common for all devices) or on the device itself. Default passwords are one of the major contributing factors to large-scale compromises of home routers. Leaving such a password on devices available to the public is a huge security risk. Some devices (such as wireless routers) will come with uniqudefault router username and passwordsprinted on a sticker, which is a more secure option than a common default password. Some vendors will however derive the password from the device's MAC address using a know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York City
New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the List of United States cities by population density, most densely populated major city in the United States, and is more than twice as populous as second-place Los Angeles. New York City lies at the southern tip of New York (state), New York State, and constitutes the geographical and demographic center of both the Northeast megalopolis and the New York metropolitan area, the largest metropolitan area in the world by urban area, urban landmass. With over 20.1 million people in its metropolitan statistical area and 23.5 million in its combined statistical area as of 2020, New York is one of the world's most populous Megacity, megacities, and over 58 million people live within of the city. New York City is a global city, global Culture of New ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phone Phreak
Phreaking is a slang term coined to describe the activity of a culture of people who study, experiment with, or explore telecommunication systems, such as equipment and systems connected to public telephone networks. The term ''phreak'' is a sensational spelling of the word ''freak'' with the ''ph-'' from ''phone'', and may also refer to the use of various audio frequencies to manipulate a phone system. ''Phreak'', ''phreaker'', or ''phone phreak'' are names used for and by individuals who participate in phreaking. The term first referred to groups who had reverse engineered the system of tones used to route long-distance calls. By re-creating these tones, phreaks could switch calls from the phone handset, allowing free calls to be made around the world. To ease the creation of these tones, electronic tone generators known as blue boxes became a staple of the phreaker community. This community included future Apple Inc. cofounders Steve Jobs and Steve Wozniak. The blue box er ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decoder (phreak)
Decoder may refer to: Technology * Audio decoder converts digital audio to analog form * Binary decoder, digital circuits such as 1-of-N and seven-segment decoders * Decompress (compression decoder), converts compressed data (e.g., audio/video/images) to an uncompressed form * Instruction decoder, an electronic circuit that converts computer instructions into CPU control signals * Quadrature decoder, converts signals from an incremental encoder into counter control signals * Video decoder, converts base-band analog video to digital form Music * Decoder (band), a defunct post-hardcore band that was briefly named ''Lead Hands'' * Decoder (duo), a drum and bass duo * ''Decoder'' (album) Other uses * ''Decoder'' (film), a 1984 West German film See also * Decoding methods * Code (other) * Recode (other) ''Recode'' is a technology news website. Recode or recoding may also refer to: * Recode (database), a biological database * Recode, an act or product of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verizon
Verizon Communications Inc., commonly known as Verizon, is an American multinational telecommunications conglomerate and a corporate component of the Dow Jones Industrial Average. The company is headquartered at 1095 Avenue of the Americas in Midtown Manhattan, New York City, but is Delaware General Corporation Law, incorporated in Delaware. The company was formed in 1984 as Bell Atlantic as part of the breakup of the Bell System, break up of the Bell System into seven companies, each a Regional Bell Operating Company (RBOC), commonly referred to as "Baby Bells". Headquartered in Philadelphia, it originally had an operating area from New Jersey to Virginia. In 1997, Bell Atlantic expanded into New York (state), New York and the New England states by merging with fellow Baby Bell NYNEX. While Bell Atlantic was the surviving company, the merged company moved its headquarters from Philadelphia to NYNEX's old headquarters in New York City. In 2000, Bell Atlantic acquired GTE, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Telephone Exchange")
