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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) is the aggregate of the world's telephone networks that are operated by national, regional, or local telephony operators. It provides infrastructure and services for public telephony. The PSTN consists of telephone lines, fiber-optic cables, microwave transmission links, cellular networks, communications satellites, and undersea telephone cables interconnected by switching centers, such as central offices, network tandems, and international gateways, which allow telephone users to communicate with each other. Originally a network of fixed-line analog telephone systems, the PSTN is now predominantly digital in its core network and includes terrestrial cellular, satellite, and landline systems. These interconnected networks enable global communication, allowing calls to be made to and from nearly any telephone worldwide. Many of these networks are progressively transitioning to Internet Protocol to carry their telephony tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Exchange
A telephone exchange, telephone switch, or central office is a central component of a telecommunications system in the public switched telephone network (PSTN) or in large enterprises. It facilitates the establishment of communication circuits, enabling telephone calls between subscribers. The term "central office" can also refer to a central location for fiber optic equipment for a fiber internet provider. In historical perspective, telecommunication terminology has evolved with time. The term ''telephone exchange'' is often used synonymously with ''central office'', a Bell System term. A central office is defined as the telephone switch controlling connections for one or more central office prefixes. However, it also often denotes the building used to house the inside plant equipment for multiple telephone exchange areas. In North America, the term ''wire center'' may be used to denote a central office location, indicating a facility that provides a telephone with a dial tone ... [...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 swit ... [...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. On some systems before the off-hook tone is played, an intercept message may be announced. The most ... [...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 to access the device 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, expecting users to change the password during configuration. The default username and password are 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 major security risk. There are several Proof-of-Concept (POC), as well as real world worms running across internet, which are configured to search for systems set with a default username and password. Voyager Alpha Force, Zotob, and MySpooler are a few examples of POC malware which scan the Internet for specific devices a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York City
New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive with a respective county. The city is the geographical and demographic center of both the Northeast megalopolis and the New York metropolitan area, the largest metropolitan area in the United States by both population and urban area. New York is a global center of finance and commerce, culture, technology, entertainment and media, academics, and scientific output, the arts and fashion, and, as home to the headquarters of the United Nations, international diplomacy. With an estimated population in 2024 of 8,478,072 distributed over , the city is the most densely populated major city in the United States. New York City has more than double the population of Los Angeles, the nation's second-most populous city. [...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 the signaling tones, phreaks could switch calls from the phone handset while avoiding long-distance calling charges which were common then. These fees could be significant, depending on the time, duration and destination of the call. To ease the creation of the routing tones, electronic tone generators known as blue boxes became a stap ... [...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) A code is a rule for converting a piece of information into another object or action, not necessarily of the same sort. Code may also refer to: Computing * Code (metadata), data elem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verizon
Verizon Communications Inc. ( ), is an American telecommunications company headquartered in New York City. It is the world's second-largest telecommunications company by revenue and its mobile network is the largest wireless carrier in the United States, with 146 million subscribers as of March 31, 2025. The company was formed in 1983 as Bell Atlantic as a result of the breakup of the Bell System into seven companies, each a Regional Bell Operating Company (RBOC), commonly referred to as "Baby Bells." The company was originally headquartered in Philadelphia and operated in the states of Pennsylvania, New Jersey, Delaware, Maryland, Virginia, and West Virginia. In 1997, Bell Atlantic expanded into 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, which oper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
