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79-458: Demarcation point is sometimes abbreviated as demarc , DMARC , or similar. The term MPOE ( minimum or main point of entry ) is synonymous, with the added implication that it occurs as soon as possible upon entering the customer premises. A network interface device often serves as the demarcation point. Prior to Federal Communications Commission (FCC) regulations separating the ownership of customer premises telecommunication equipment from

158-408: A patch panel of telephone wires on the wall next to a series of boxes with RJ48 jacks for T-1 lines . Each business or individual customer can expect their own separate box for internet access T-1 lines. A demarcation point extension , or demarc extension is the transmission path originating from the interface of the access provider's side of a demarcation point within a premises and ending at

237-460: A utility pole . Simple NIDs are "dumb" devices, as they contain no digital logic . They have no capabilities beyond wiring termination, circuit protection, and providing a place to connect test equipment. Several types of NIDs provide more than just a terminal for the connection of wiring. Such NIDs are colloquially called smartjacks or Intelligent Network Interface Devices (INIDs) as an indication of their built-in "intelligence", as opposed to

316-482: A 4P4C connector. The two center pins are commonly used for the receiver, and the outer pins connect the transmitter so that a reversal of conductors between the ends of a cord does not affect the signal routing. This may differ for other equipment, including hands-free headsets. The Macintosh 128K , Macintosh 512K and Macintosh Plus from Apple as well as the Amiga 1000 from Commodore use 4P4C connectors to connect

395-484: A building's telecommunications infrastructure after the 1984 deregulation of AT&T as well as the supplemental FCC rulings of 1991, 1996 and 1997. Preceding these rulings, the Bell System Companies held a monopoly and did not allow an interconnection with third party equipment. The incumbent local exchange carriers (ILEC) and other local access providers are now mandated by federal law to provide

474-427: A central junction box . Two of its six possible contact positions connect tip and ring , and the other two contact positions may be unused or provide low-voltage power for night light or other features on the telephone set. In some installations, an extra contact was also required for the ground connection for selective ringers . The pins of the 6P6C connector are numbered 1 to 6, counting left to right when holding

553-431: A computer serial port to control the set-top box. Modular plugs are described by the maximum number of physical contact positions and the actual number of contacts installed in these positions. The 6P2C , 6P4C , and 6P6C modular connectors are probably best known for their use as RJ11 , RJ14 , and RJ25 non-powered registered jacks, respectively (and 6P4C and 6P6C for powered RJ11 and RJ14, power being delivered on

632-450: A given plug is designed for only one type. The sharp prongs are different in the connectors made for each type of wire, and a mismatch between plug type and wire type results in unreliable connections. A modular plug for solid (single-strand) wire often has three slightly splayed prongs on each contact to securely surround and grip the conductor while scraping along the outside, and a plug for stranded wire has prongs that are designed to pierce

711-452: A key that excludes insertion in an un-keyed 8P8C socket. The original RJ45S was intended for high-speed modems and is obsolete. The RJ45S jack mates with a keyed 8P2C modular plug, and has pins 4 and 5 (the middle positions) wired for the ring and tip conductors of a single telephone line and pins 7 and 8 shorting a programming resistor. This is a different mechanical interface and wiring scheme than ANSI/TIA-568 T568A and T568B schemes with

790-458: A large number of manufacturers, whereas Tyco/AMP plugs are produced exclusively by Tyco Electronics . Both types of modular plugs can be mated with a standard 8P8C modular jack. Both types of 8P8C plugs are available in shielded and unshielded varieties for different attenuation tolerances as needed. Shielded plugs are more expensive and require shielded cable, but have a lower attenuation, and may reduce electromagnetic interference . Although

869-515: A larger restructuring of the domestic telecommunications industry which took place during the 1980s and are commonly, if inaccurately, seen as one event. The historical Bell System domination of the United States telecommunications industry was also the de facto standard for other telephone companies such as GTE and other “independent” telephone companies. The demarcation point varies from building type and service level. In its simplest form,

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948-424: A modular plug on one end and a jack on the other are rare. Instead, cables are usually connected using a female-to-female coupler, having two jacks wired back-to-back. Most modular connectors are designed with a latching mechanism that secures the physical connection. As a plug is inserted into a jack, a plastic tab on the plug locks against a ridge in the socket so that the plug cannot be removed without disengaging

1027-608: A narrower 4-pin and 6-pin plug fits into the wider 8-pin jack and makes a connection with the available contacts on the plug, because the body of the smaller connector may stress the remaining contacts, the smaller connector can potentially damage the springs of the larger jack. 8P8C connectors are commonly used in computer networking applications, where interconnecting cables are terminated at each end with an 8P8C modular plug wired according to TIA/EIA standards. Most wired Ethernet communications are carried over Category 5e or Category 6 cable terminated with 8P8C modular plugs. The connector

1106-410: A nominally incompatible wider jack. Termination of cables with modular connectors is similar across the various number of positions and contacts in the plug. The crimping tool contains a die that is often exchangeable and is closely matched to the shape and pin count of the modular plug. A crimping die-set looks similar to an 8P8C jack, except for the eight teeth lining the top portion of the die. When

1185-411: A one-, two-, or three-line jack . The contact positions are numbered sequentially starting from 1. When viewed head-on with the retention mechanism on the bottom, jacks will have contact position number 1 on the left and plugs will have it on the right. Contacts are numbered by the contact position. For example, on a six-position, two-contact plug, where the outermost four positions do not have contacts,

1264-460: A point where the operational control or ownership changes. This separation between the local access provider and the end user/subscriber is called the demarcation point within a facility (typically a short distance from the minimum point of entry). This then becomes the responsibility of the end user to extend their service to the CPE location within a facility to provide connectivity for service, requiring

1343-460: A polarized straight-through pinout. Using a telephone handset cable instead of the supplied cable could short out the +5 volt DC supply and damage the Apple computer or the keyboard. Modular connectors are often used for data links, such as serial line connections, because of their compact dimensions. For example, some DirecTV set-top boxes include a 4P4C data port with an adapter cord to connect to

1422-516: A service interface extension, or otherwise called a demarc extension. In the United Kingdom, the demarcation point occurs on the LJU master socket, whose wiring is partly owned by the customer, partly owned by the phone company. Other secondary sockets are the customer's property. Newer NTE-5 master phone sockets have a removable front panel: the front panel and its wiring is the customer's, while

1501-536: A simple NID, which is just a wiring device. Smartjacks are typically used for more complicated types of telecommunications service, such as T1 lines . Plain old telephone service lines generally cannot be equipped with smartjacks. Despite the name, most smartjacks are much more than a simple telephone jack . One common form for a smartjack is a printed circuit board with a face plate on one edge, mounted in an enclosure. A smartjack may provide signal conversion, converting codes and protocols, e.g. , framing types, to

1580-444: A switch or hub, however, most network interface cards (NIC) in use today implement auto MDI-X to automatically configure themselves based on the type of cable plugged into them. A cable wired the same at both ends is called a patch or straight-through cable , because no pin/pair assignments are swapped. If a patch or straight cable is used to connect two computers with auto MDI-X capable NICs, one NIC will configure itself to swap

1659-406: Is a type of electrical connector for cords and cables of electronic devices and appliances, such as in computer networking , telecommunication equipment, and audio headsets. Modular connectors were originally developed for use on specific Bell System telephone sets in the 1960s, and similar types found use for simple interconnection of customer-provided telephone subscriber premises equipment to

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1738-416: Is also used in other telecommunications connections, including ISDN and T1 . Where building network and telephone wiring is pre-installed, the center (blue) pair is often used to carry telephony signals. While this allows an RJ11 plug to connect, it may damage the modular jack; an approved converter prevents damage. In landline telephony, an 8P8C jack is used at the point a line enters the building to allow

1817-491: Is called the demarcation point, or Demarc, which includes one or more customer-accessible jack interfaces; previously, the interface was typically hard-wired and often in a telephone company-owned locked enclosure. The premises-vs.-network separation in the United States, insofar as it affected the former Bell System , was independent of AT&T's divestiture of the local telephone companies on January 1, 1984. However, CPE interconnection and Bell System divestiture were part of

1896-432: Is connected directly to the telephone network, and a small loop of telephone cord connecting to the jack by a modular connector . When the loop is disconnected, the on-premises wiring is isolated from the telephone network and the customer may directly connect a telephone to the network via the jack to assist in determining the location of a wiring fault. In most cases, everything from the central office to and including

1975-715: Is specified by the ANSI/TIA-568 standard. For other applications, standardization may be lacking; for example, multiple conventions exist for the use of 8P8C connectors in RS-232 applications. For this reason, D-sub -to-modular adapters are typically shipped with the D-sub contacts (pins or sockets) terminated but not inserted into the connector body so that the D-sub-to-modular contact pairing can be assigned as needed. The four-position four-conductor ( 4P4C ) connector

2054-450: Is that the orange and green pairs (colors) are swapped. A cable wired as T568A at one end and wired as T568B at the other end (Tx and Rx pairs reversed) is an Ethernet crossover cable . Before the widespread acceptance of auto MDI-X capabilities, a crossover cable was needed to interconnect similar network equipment (such as Ethernet hubs to Ethernet hubs). Crossover cables are sometimes still used to connect two computers together without

2133-403: Is the standard modular connector used on both ends of telephone handset cords and is therefore often called a handset connector . This handset connector is not a registered jack, because it was not intended to connect directly to telephone lines. However, it is often referred to as RJ9 , RJ10 , or RJ22 . [REDACTED] Handsets and often headsets for use with telephones commonly use

2212-399: The ANSI/TIA-568 (formerly TIA/EIA-568) and Yost standards, and other applications involving unshielded twisted pair , shielded twisted pair , and multi-conductor flat cable. An 8P8C modular connection consists of a male plug and a female jack, each with eight equally spaced contacts. On the plug, the contacts are flat metal bars positioned parallel to the connector body. Inside the jack,

2291-512: The Western Electric Company in the 1960s. This includes the 6P2C used for telephone line connections and 4P4C used for handset connectors. Registered jack designations describe the signals and wiring used for voice and data communication at customer-facing interfaces of the public switched telephone network (PSTN). It is common to use a registered jack number to refer to the physical connector itself; for instance,

2370-515: The demarcation point between the carrier's local loop and the customer's premises wiring . Outdoor telephone NIDs also provide the subscriber with access to the station wiring and serve as a convenient test point for verification of loop integrity and of the subscriber's inside wiring. Generically, an NID may also be called a network interface unit (NIU), telephone network interface (TNI), system network interface (SNI), or telephone network box . Australia's National Broadband Network uses

2449-583: The 8P8C connector in Ethernet and telephone applications. Generic 8P8C modular connectors are similar to those used for the RJ45S variant, although the RJ45S plug is keyed and not compatible with non-keyed 8P8C modular jacks. Telephone installers who wired RJ45S modem jacks or RJ61X telephone jacks were familiar with the pin assignments of the standard. However, the standard un-keyed modular connectors became ubiquitous for computer networking and informally inherited

Demarcation point - Misplaced Pages Continue

2528-448: The NID and all wiring up to it. Anything past the NID is the customer's responsibility. To facilitate this, there is typically a test jack inside the NID. Accessing the test jack disconnects the customer premises wiring from the public switched telephone network and allows the customer to plug a "known good" telephone into the jack to isolate trouble. If the telephone works at the test jack,

2607-464: The T568A and T568B conventions have largely displaced RJ25 and RJ61 for telephones with more than two lines. The 8 position 8 contact ( 8P8C ) connector is a modular connector commonly used to terminate twisted pair and multi-conductor flat cable . These connectors are commonly used for Ethernet over twisted pair , registered jacks and other telephone applications, RS-232 serial communication using

2686-460: The additional connectors of TAE (E, W, a2, b2) and may feature non-RJ standard sockets that can be connected directly to TAE plugs. Further, flat DIN 47100 cables typically place the wires in ascending order. When used directly with 6P4C plugs, the color coding may be undetermined. In the powered version of the RJ11 interface, pins 2 and 5 (black and yellow) may carry low-voltage AC or DC power. While

2765-933: The basis for the modular molded-plastic connectors that became commonplace for telephone cords by the 1980s. In 1976, these connectors were standardized nationally in the United States by the Registration Interface program of the Federal Communications Commission (FCC), which designated a series of Registered Jack (RJ) specifications for interconnection of customer-premises equipment to the PSTN. Modular connectors have gender : plugs are considered to be male , while jacks or sockets are considered to be female . Plugs are used to terminate cables and cords, while jacks are used for fixed locations on surfaces of walls, panels, and equipment. Other than telephone extension cables, cables with

2844-518: The best-known applications of modular connectors are for telephone and Ethernet . Accordingly, various electronic interface specifications exist for applications using modular connectors, which prescribe physical characteristics and assign electrical signals to their contacts. Modular connectors are often referred to as modular phone jack and plug , RJ connector , and Western jack and plug . The term modular connector arose from its original use in modular wiring components of telephone equipment by

2923-453: The building exterior in a weatherproof box) or indoors. The NID is usually placed for easy access by a technician. It also contains a lightning arrestor, fuse and test circuitry which allows the carrier to remotely test whether a wiring fault lies in the customer premises or in the carrier wiring, without requiring a technician at the premises. The demarcation point has a user accessible RJ-11 jack (a "test jack" or "demarcation jack"), which

3002-449: The company to test the line from the central telephone exchange , without the need to have test equipment at the customer site. The telephone company usually has the ability to remotely activate loopback, without even needing personnel at the customer site. When looped back, the customer equipment is disconnected from the line. Additional smartjack diagnostic capabilities include alarm indication signal , which reports trouble at one end of

3081-506: The company), it was necessary to provide a standardized way to connect equipment, and also provide a way to test the phone company's service separately from the customer's equipment. The ability of customers to buy and maintain their CPE and attach it to the network was stimulated by lawsuits by equipment manufacturers, such as the Hush-a-Phone v. FCC suit. Additionally, computer companies’ ability to offer enhanced services to customers

3160-426: The connector tab side down with the opening for the cable facing the viewer. However, with German domestic telephone equipment, and that in some neighboring countries, 6P4C plugs and sockets are typically only used to connect the telephone cord to the phone base unit, whereas the mechanically different TAE connector is used at the other end to connect to a service provider interface. Older base units may accommodate

3239-468: The contacts are metal spring wires angled away from the insertion interface. When the plug is mated with the jack, the contacts meet and create an electrical connection. The spring force of the jack contacts ensures a good interface. Although commonly referred to as RJ45 in the context of Ethernet and category 5 cables , RJ45 originally referred to a specific wiring configuration of an 8P8C connector. The original telephone-system-standard RJ45 plug has

Demarcation point - Misplaced Pages Continue

3318-405: The demarcation point is a junction block where telephone extensions join to connect to the network. This junction block usually includes a lightning arrester (which requires a wire to ground ). In multi-line installations such as businesses or apartment buildings, the demarcation point may be a punch down block . In most places this hardware existed before deregulation. In the United States,

3397-403: The demarcation point is owned by the carrier and everything past it is owned by the property owner. As the local loop becomes upgraded, with fiber optic and coaxial cable technologies sometimes replacing the original unshielded twisted pair to the premises, the demarcation point has grown to incorporate the equipment necessary to interface the original premises POTS wiring and equipment to

3476-419: The functions of its Tx and Rx wire pairs. Pin numbering on plug face. Connected pins on plug and jack have the same number. Two types of 8P8C plugs and crimping tools for installing the plug onto a cable are commonly available: Western Electric/Stewart Stamping (WE/SS) and Tyco/AMP. While the two types are similar, the tooling and plug types cannot be interchanged. WE/SS compatible plugs are available from

3555-430: The insulation and go straight through to contact multiple wire strands. Some modular connectors are indexed , meaning their dimensions are intentionally non-standard, preventing connections with connectors of standard dimensions. The means of indexing may be non-standard cross-sectional dimensions or shapes, retention mechanism dimensions or configuration. For example, a Modified Modular Jack using an offset latching tab

3634-505: The jacks in the house. Structured cabling networks adhering to ANSI/TIA-568 , ISO/IEC 11801 (or ISO/IEC 15018 for home networks) are widely used for both computer networking and analog telephony. These standards specify the T568A or T568B wiring arrangements compatible with Ethernet . The 8P8C jack used by structured cabling physically accepts the 6-position connector used by RJ11, RJ14 and RJ25. Only RJ11 and RJ14 have full electrical compatibility because Ethernet-compatible pin-outs split

3713-489: The keyboard to the main computer housing. The connector provides power to the keyboard on the outer two contacts and receives data signals on the inner pair. The cable between the computer and the keyboard is a coiled cord with an appearance very similar to a telephone handset cable. The connector on the Amiga 1000 uses crossover wiring, similar to a telephone handset. The connector wiring on the Apple computers, however, requires

3792-465: The line to be broken to insert automatic dialing equipment, including intrusion alarm panels. The EIA /TIA-561 standard describes the use of 8P8C connectors for RS-232 serial interfaces. This application is common as a console interface for network equipment , such as switches , routers , and headless computers . 8P8C modular connectors are also commonly used as a microphone connectors for PMR , LMR , and amateur radio transceivers. Frequently

3871-413: The line to the far end. This helps the telephone company know if trouble is present in the line, the smartjack, or customer equipment. Indicator lights to show configuration, status, and alarms are also common. Smartjacks typically derive their operating power from the telephone line, rather than relying on premises electrical power, although this is not a universal rule. In fiber-to-the-premises systems,

3950-719: The mid-1960s for the plug-in handset and line cords of the Trimline telephone. Driven by demand for multiple sets in residences with various lengths of cords, the Bell System introduced customer-connectable part kits and telephones, sold through PhoneCenter stores in the early 1970s. For this purpose, Illinois Bell started installing modular telephone sets on a limited scale in June 1972. The patents by Edwin C. Hardesty and coworkers, US 3699498   (1972) and US 3860316   (1975), followed by other improvements, were

4029-543: The modern demarcation point is a device defined by FCC rules (47 C.F.R. Part 68) to allow safe connection of third-party telephone customer-premises equipment and wiring to the Public Switched Telephone Network (PSTN). The modern demarcation point is the network interface device (NID) or intelligent network interface device (INID) also known as a "smartjack". The NID is the telco's property. The NID may be outdoors (typically, mounted on

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4108-709: The name RJ45 . The shape and dimensions of an 8P8C modular connector are specified for US telephone applications by the Administrative Council for Terminal Attachment (ACTA) in national standard ANSI /TIA-1096-A and international standard ISO-8877. This standard does not use the short term 8P8C and covers more than just 8P8C modular connectors, but the 8P8C modular connector type is the eight-position connector type described therein, with eight contacts installed. For data communication applications ( LAN , structured cabling ), International Standard IEC 60603 specifies in parts 7-1, 7-2, 7-4, 7-5, and 7-7 not only

4187-531: The new communication channel. Demarcation points on houses built prior to the Bell System divestiture usually do not contain a test jack. They only contained a spark-gap surge protector, a grounding post and mount point to connect a single telephone line. The second wire pair was usually left unconnected and were kept as a spare pair in case the first pair was damaged. DEMARCs that handle both telephony and IT fiber optic internet lines often do not look like

4266-461: The ones pictured above. In many places several customers share one central DEMARC for a commercial or strip mall setting. Usually a DEMARC will be located indoors if it is serving more than a single customer. This may impede access. Outdoor ones provide easier access, without disturbing other tenants, but call for weatherproofing and punching through a wall for each new addition of wires and service. Typically indoor DEMARC's will be easily identified by

4345-499: The outer pairs). These interfaces use the same six-position modular connector body but have different numbers of pins installed. RJ11 is a physical interface often used for terminating single telephone lines. RJ14 is similar, but for two lines, and RJ25 is for three lines. RJ61 is a similar registered jack for four lines, but uses an 8P8C connector. Cables sold as RJ11 often actually use 6P4C connectors (six positions, four contacts) and RJ14 wiring – four wires running to

4424-477: The outermost contacts in the jack are forcibly deformed. Special modular plugs have been manufactured (for example, the Siemon UP-2468 ) which have extra slots beyond their standard contacts, to accommodate the wider jack's outermost contacts without damage. These special plug connectors can be visually identified by carefully looking for the extra slots molded into the plug. The molded plastic bodies of

4503-442: The outside of the building. The telephone line from the telephone company will enter the NID and be connected to one side. The customer connects their wiring to the other side. A single NID enclosure may contain termination for a single line or multiple lines. In its role as the demarcation point (dividing line), the NID separates the telephone company's equipment from the customer's wiring and equipment. The telephone company owns

4582-536: The position and contact quantities with either an x ( 6x2 ) or a slash ( 6/2 ). When not installed, contacts are usually omitted from the outer positions inward, such that the number of contacts is almost always even. The connector body positions with omitted or unconnected contacts are unused for the electrical connection but ensure that the plug fits correctly. For instance, inexpensive telephone cords often have connectors with six positions and four contacts, to which are attached just two wires, carrying only line 1 from

4661-416: The problem is the customer's wiring, and the customer is responsible for repair. If the telephone does not work, the line is faulty and the telephone company is responsible for repair. Most NIDs also include "circuit protectors", which are surge protectors for a telephone line. They protect customer wiring, equipment, and personnel from any transient energy on the line, such as from a lightning strike to

4740-399: The protective boot before the modular plug is crimped. Modular connectors are designated using two numbers that represent the maximum number of contact positions and the number of installed contacts, with each number followed by P and C , respectively. For example, 6P2C is a connector having six positions and two installed contacts. Alternate designations omit the letters while separating

4819-419: The rear wiring is Openreach's. The removable panel allows separation of these two parts and independent maintenance, and access to a test socket to determine whether line faults are in the customer's wiring or Openreach's (formerly BT's) external network. Network interface device In telecommunications , a network interface device ( NID ; also known by several other names) is a device that serves as

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4898-454: The regular 8P8C modular connector type is often labeled RJ45 because the registered jack standard of the similar name RJ45S specified a similar, but modified, 8P8C modular connector. Similarly, various six-position modular connectors may be called RJ11 . Likewise, the 4P4C connector is sometimes called RJ9 or RJ22 though no such official designations exist. The first types of small modular telephone connectors were created by AT&T in

4977-473: The same physical dimensions but also high-frequency performance requirements for shielded and unshielded versions of this connector for carrying frequencies up to 100, 250 and 600  MHz . 8P8C connectors are frequently terminated using the T568A or T568B assignments that are defined in ANSI/TIA-568. The drawings to the right show that the copper connections and pairing are the same, the only difference

5056-987: The signal into its component parts (voice telephone , television , and Internet access ), and provide power to customer telephones. If the device combines all these services into one it is known as an IAD . As the ONT must derive its power from the customer premises electrical supply, many ONTs have the option for a battery backup in order to maintain service in the event of a power outage . These terminals are used in both active optical networks and passive optical networks . An ONT can work in Single Family Unit/SFU mode (modem/bridge) or Home Gateway Unit/HGU mode (router). According to Telcordia GR-49 requirements for telecommunications, NIDs vary based on three categories of environmental conditions: Service providers must decide which condition best suits their application. Modular connector A modular connector

5135-430: The signal is transmitted to the customer premises using optical fiber technologies. Unlike many conventional telephone technologies, this does not provide power for premises equipment, nor is it suitable for direct connection to customer equipment. An optical network terminal ( ONT , an ITU-T term), also known as an optical network unit ( ONU , an IEEE term), is used to terminate the optical fiber line, demultiplex

5214-405: The special plugs may also be colored with a light blueish tinge, to aid in quick recognition. The special plugs are preferred for test equipment and adapters, which may be rapidly connected to a large number of corresponding connectors in quick succession for testing purposes. The use of the special plugs avoids inadvertent damage to the equipment under test, even when a narrower plug is inserted into

5293-421: The tab by pressing it against the plug body. The standard orientation for installing a jack in a vertical surface is with the tab down. The modular plug is often installed with a boot , a plastic covering over the tab and body, to prevent the latching tab from hooking into other cords or edges, which may cause excessive bending or breaking of the tab. Such snagless cords are usually constructed by installing

5372-497: The telephone line on pins 3 and 4 (red and green) supplies enough power for most telephone terminals, old telephone terminals with incandescent lights, such as the Western Electric Princess and Trimline telephones , need more power than the phone line can supply. Typically, the power on pins 2 and 5 is supplied by an AC adapter plugged into a nearby power outlet which potentially even supplies power to all of

5451-477: The telephone network, there was no need for a public standard governing the interconnection of customer premises equipment (CPE) to the United States' telephone network, since both the devices and the “local loop” wiring to the central office were owned and maintained by the local telephone company. Concurrent with the transfer of existing "embedded" CPE to the customer (customers could buy new telephones at retail or could continue to lease their existing equipment from

5530-429: The telephone network. The Federal Communications Commission (FCC) mandated in 1976 an interface registration system, in which they became known as registered jacks . The convenience of prior existence for designers and ease of use led to a proliferation of modular connectors for many other applications. Many applications that originally used bulkier, more expensive connectors have converted to modular connectors. Probably

5609-420: The term network termination device or NTD. A smartjack is a type of NID with capabilities beyond simple electrical connection, such as diagnostics. An optical network terminal (ONT) is a type of NID used with fiber-to-the-premises applications. The simplest NIDs are essentially just a specialized set of wiring terminals . These will typically take the form of a small, weather-proof box, mounted on

5688-506: The termination point prior to the interface of the edge Customer Premises Equipment (CPE). This may include in-segment equipment, media converters and patch cords as required to complete the circuit's transmission path to the edge CPE. A demarc extension is more correctly termed "Service Interface Extension", and may also be referred to as inside wiring, extended demarc, circuit extension, CPE cabling, riser cabling or DMARC extension. A demarc extension became an important factor to consider in

5767-454: The third pair of RJ25 across two separate cable pairs, rendering that pair unusable by an analog phone. Both the third and fourth pairs of RJ61 are similarly split. The incompatible T568A and T568B layouts were necessary to preserve the electrical properties of the third and fourth pairs for Ethernet, which operates at much higher frequencies than analog telephony. Because of these incompatibilities, and because RJ25 and RJ61 were never very common,

5846-591: The tool is operated, the die compresses around the 8P8C plug. As the die compresses, these teeth force the plug contacts into the conductors of the cable being terminated. The crimper may also permanently deform part of the plastic plug body in such a way that it grips the outer sheath of the cable for secure fastening and strain relief . These actions permanently attach the plug to the cable. The contact assignments ( pinout ) of modular connectors vary by application. Telephone network connections are standardized by registered jack designations, and Ethernet over twisted pair

5925-537: The two contacts are numbered 3 and 4. Modular connectors are manufactured in four sizes, with four, six, eight, and ten positions. The insulating plastic bodies of 4P and 6P connectors have different widths, whereas 8P or 10P connectors share an even larger body width. Internally, the contacts in the plugs have sharp prongs that, when crimped , displace the wire insulation and connect with the conductors inside—a mechanism known as insulation displacement . Cables have either solid or stranded ( tinsel wire ) conductors, and

6004-413: The type needed by the customer equipment. It may buffer and/or regenerate the signal, to compensate for signal degradation from line transmission, similar to what a repeater does. Smartjacks also typically provide diagnostic capabilities. A very common capability provided by a smartjack is loopback , such that the signal from the telephone company is transmitted back to the telephone company. This allows

6083-482: The width is dependent on the number of pin positions. However, not all plugs from all manufacturers have this capability, and some jack manufacturers warn that their jacks are not designed to accept smaller plugs without damage. If an inserted plug lacks slots to accommodate the jack's contacts at the outermost extremes, it may permanently deform those outermost contacts of an incompatible jack. Excessive resistance may be encountered when inserting an incompatible plug, as

6162-461: Was developed by Digital Equipment Corporation to prevent accidental interchange of data and telephone cables. The dimensions of modular connectors are such that a narrower plug can be inserted into a wider jack that has more positions than the plug, leaving the jack's outermost contacts unconnected. The height of the plug's insertion area is 0.260 inches (6.60 mm) and the contacts are 0.040 inches (1.02 mm) apart (contact pitch), so

6241-652: Was likewise constrained by the telephone companies’ control of all devices connected to the network. As the Bell telephone companies were themselves restricted from offering such enhanced services, there was little momentum to advance the state of the art. The newly developed equipment-network separation was codified in Part 68 of the Code of Federal Regulations in the United States and later in comparable regulatory standards in other countries. The physical and electrical interconnection

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