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Lineman's Handset
A lineman's handset is a special type of telephone used by technicians for installing and testing local loop telephone lines. It is also called a test set, butt set, or buttinski. Components A typical lineman's handset integrates an earpiece, a mouthpiece, a dialing interface, and a set of test leads for connecting to the telephone circuit. Originally, lineman's handsets featured a rotary dial, but modern sets use some variant of the standard 12-button DTMF keypad and also employ an amplifier for speaker use. Most handsets are designed to be used with analog " POTS" lines, and have limited or no function with digital circuits. Older Telephone linemen also referred to the Buttset as a "Goat". In addition to the basic features listed above, handsets often include one or more of: * Speakerphone * Redial * A talk/monitor toggle switch * Mute * Hook flash button * Tone/pulse dialing selection switch * Low-pass filtering to prevent disruption of data communications (such as DSL) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Technician Checking Lines
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 Electrical cable, 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 te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-pass Filter
A low-pass filter is a filter that passes signals with a frequency lower than a selected cutoff frequency and attenuates signals with frequencies higher than the cutoff frequency. The exact frequency response of the filter depends on the filter design. The filter is sometimes called a high-cut filter, or treble-cut filter in audio applications. A low-pass filter is the complement of a high-pass filter. In optics, high-pass and low-pass may have different meanings, depending on whether referring to frequency or wavelength of light, since these variables are inversely related. High-pass frequency filters would act as low-pass wavelength filters, and vice versa. For this reason it is a good practice to refer to wavelength filters as ''short-pass'' and ''long-pass'' to avoid confusion, which would correspond to ''high-pass'' and ''low-pass'' frequencies. Low-pass filters exist in many different forms, including electronic circuits such as a hiss filter used in audio, anti-aliasing fil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross-connect Box
A digital cross-connect system (DCS or DXC) is a piece of circuit-switched network equipment, used in telecommunications networks, that allows lower-level TDM bit streams, such as DS0 bit streams, to be rearranged and interconnected among higher-level TDM signals, such as DS1 bit streams. DCS units are available that operate on both older T-carrier/E-carrier bit streams, as well as newer SONET/SDH bit streams. DCS devices can be used for " grooming" telecommunications traffic, switching traffic from one circuit to another in the event of a network failure, supporting automated provisioning, and other applications. Having a DCS in a circuit-switched network provides important flexibility that can otherwise only be obtained at higher cost using manual " DSX" cross-connect patch panels. It is important to realize that while DCS devices "switch" traffic, they are ''not'' packet switches—they switch ''circuits'', not packets, and the circuit arrangements they are used to man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serving Area Interface
The serving area interface or service area interface (SAI) is an outdoor enclosure or metal box that allows access to telecommunications wiring. Alternate names *Access point (AP) *Cabinet (cab) *B-box (breakout box) *Cross box *Cross-connect box *Jumper wire interface (JWI) *Outside plant interface (OPI) *Pedestal (ped) *Primary cross-connection point (PCP) (UK)"Multimedia Telecommunications" (BT Telecommunications Series), B. Whyte (Ed.), Springer 1997 *Secondary cross-connection point (SCP) (UK) *Telecom cabinet Function The SAI provides the termination of individual twisted pairs of a telephony local loop for onward connection back to the nearest telephone exchange (US: " central office" (CO)) or remote switch, or first to transmission equipment such as a subscriber loop carrier multiplexer and then to the exchange main distribution frame (MDF). In the United Kingdom, the components from the PCP onwards to the customer are known as "D-side" (distribution side), and from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outside Plant
In telecommunication, the term outside plant has the following meanings: *In civilian telecommunications, outside plant refers to all of the physical cabling and supporting infrastructure (such as conduit, cabinets, tower or poles), and any associated hardware (such as repeaters) located between a demarcation point in a switching facility and a demarcation point in another switching center or customer premises. *In the United States, the DOD defines outside plant as the communications equipment located between a main distribution frame (MDF) and a user end instrument. The CATV industry divides its fixed assets between head end or inside plant, and outside plant. The electrical power industry also uses the term outside plant to refer to electric power distribution systems. Context Network connections between devices such as computers, printers, and phones require a physical infrastructure to carry and process signals. Typically, this infrastructure will consist of: * Cabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intermediate Distribution Frame
An intermediate distribution frame (IDF) is a distribution frame in a central office or customer premises, which cross connects the user cable media to individual user line circuits and may serve as a distribution point for multipair cables from the main distribution frame (MDF) or combined distribution frame (CDF) to individual cables connected to equipment in areas remote from these frames. IDFs are used for telephone exchange central office, customer-premises equipment, wide area network (WAN), and local area network (LAN) environments, among others. In central office environments the IDF may contain circuit termination equipment from various auxiliary components. In WAN and LAN environments IDFs can hold devices of different types including backup systems (hard drives or other media as self-contained, or as RAIDs, CD-ROMs, etc.), networking (switches, hubs, routers), and connections ( fiber optics, coaxial In geometry, coaxial means that several three-dimensional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Distribution Frame
In telephony, a main distribution frame (MDF or main frame) is a signal distribution frame for connecting equipment (inside plant) to cables and subscriber carrier equipment (outside plant). Overview The MDF is a termination point within the local telephone exchange where exchange equipment and terminations of local loops are connected by jumper wires at the MDF. All cable copper pairs supplying services through user telephone lines are terminated at the MDF and distributed through the MDF to equipment within the local exchange e.g. repeaters and DSLAM. Cables to intermediate distribution frames (IDF) terminate at the MDF. Trunk cables may terminate on the same MDF or on a separate trunk main distribution frame (TMDF). Like other distribution frames the MDF provides flexibility in assigning facilities, at lower cost and higher capacity than a patch panel. The most common kind of large MDF is a long steel rack accessible from both sides. On one side, termination blocks are ... [...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] |
Point Of Appearance
Point of appearance is a generic term for any point in a telephone/data circuit from which a technician can test or pull stats. Some appearances are virtual, such as a Digital cross connect system computer terminal. Others are physical, like a punch down COSMIC frame where a technician can place a test set, or a heat coil socket. In the outside plant there is an appearance at the cross box, pedestal, and network interface device. The ultimate appearance is the telephone or other customer premises equipment (CPE). See also *Demarcation point *Point of presence A point of presence (PoP) is an artificial demarcation point or network interface point between communicating entities. A common example is an ISP point of presence, the local access point that allows users to connect to the Internet with their ... Communication circuits {{Tech-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Coil
Heat coils, also known as ''protectors'', ''bugs'' or ''carbons'' serve as a surge protector between the telephone exchange and outside plant. They are commonly the last point of appearance for a telephone circuit before it leaves the office, for example on the outside plant side of the main distribution frame. On some competitive local exchange carrier circuits there are two heat coils, the extra one being at the point of interface between their circuit and where the incumbent local exchange carrier or Regional Bell Operating Company receives it. Their primary purpose is to protect central office equipment from surges of high voltage. If a surge comes down the line it will melt the connection between the central office and outside plant sides, as in a fuse Fuse or FUSE may refer to: Devices * Fuse (electrical), a device used in electrical systems to protect against excessive current ** Fuse (automotive), a class of fuses for vehicles * Fuse (hydraulic), a device used in hydra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adapter
An adapter or adaptor is a device that converts attributes of one electrical device or system to those of an otherwise incompatible device or system. Some modify power or signal attributes, while others merely adapt the physical form of one connector to another. Travel adapters Many countries with ties to Europe use 230-volt, 50 Hz AC mains electricity, using a variety of power plugs and sockets. Difficulty arises when moving an electrical device between countries that use different sockets. A passive electric power adapter, sometimes called a ''travel plug'' or ''travel adapter'', allows using a plug from one region with a foreign socket. As other countries supply 120-volt, 60 Hz AC, using a travel adapter in a country with a different supply poses a safety hazard if the connected device does not support both input voltages. AC-to-DC adapters An AC-to-DC power supply adapts electricity from household mains voltage (either 120 or 230 volts AC) to low-voltage DC suitable fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Punch Block
A punch-down block (also punchdown block, punch block, punchblock, quick-connect block and other variations) is a type of electrical connection often used in telephony. It is named because the solid copper wires are "punched down" into short open-ended slots which are a type of insulation-displacement connector. These slots, usually cut crosswise (not lengthwise) across an insulating plastic bar, contain two sharp metal blades which cut through the wire's insulation as it is punched down. These blades hold the wire in position and make the electrical contact with the wire as well. Overview A tool called a punch down tool is used to push the wire down firmly and properly into the slot. Some will automatically cut any excess wire off. The exact size and shape of the tool blade varies by manufacturer, which can cause problems for those working on existing installations, especially when there is a poorly documented mix of different brands. Punch-down blocks are a very quick and e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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