Cat5 cables with RJ45 connectors, wired to EIA/TIA-568B

An RJ45 connector that has yet to be crimped onto a cable

RJ45 (Registered Jack 45) is a physical interface often used for terminating twisted pair type cables. "RJ" stands for Registered Jack which is part of the United States Code of Federal Regulations. It has eight "pins" or electrical connections per connector. Download high resolution version (1492x1464, 39 KB)Cat5 cables with RJ45 plugs. ... Download high resolution version (1492x1464, 39 KB)Cat5 cables with RJ45 plugs. ... Image File history File links Download high resolution version (1100x826, 120 KB) Summary Close-up photo of an uncrimped, transparent RJ-45 plug. ... Image File history File links Download high resolution version (1100x826, 120 KB) Summary Close-up photo of an uncrimped, transparent RJ-45 plug. ... An electrical connector is a device for joining electrical circuits together. ... 25 Pair Color Code Chart 10BASE-T UTP Cable Twisted pair cabling is a common form of wiring in which two conductors are wound around each other for the purposes of cancelling out electromagnetic interference known as crosstalk. ... A registered jack (RJ) is a type of telephone jack. ... The United States Code of Federal Regulations (CFR) is the codification of the general and permanent rules and regulations published in the Federal Register by the executive departments and agencies of the Federal Government. ... PIN can mean different things: Personal identification number Postal Index Number Personal Internet Name. ...

Wiring

It is frequently terminated using the T568A or T568B pin/pair assignments that are defined in TIA/EIA-568-B: Cat5 cables with RJ45 connectors wired to T568B TIA/EIA-568-B is a set of three standards that address commercial building cabling for telecommunications products and services. ...

RJ45 Wiring (EIA/TIA-568B T568A/T568B)

Pin	T568A Pair	T568B Pair	Wire	T568A Color	T568B Color	Pins on plug (jack is reversed)
1	3	2	tip	white/green stripe	white/orange stripe
2	3	2	ring	green solid	orange solid
3	2	3	tip	white/orange stripe	white/green stripe
4	1	1	ring	blue solid	blue solid
5	1	1	tip	white/blue stripe	white/blue stripe
6	2	3	ring	orange solid	green solid
7	4	4	tip	white/brown stripe	white/brown stripe
8	4	4	ring	brown solid	brown solid

The original concept (RJ11, RJ14, RJ25, RJ48, RJ61) was that the central two pins would be one pair, the next two out the second pair, and so on until the outer pins of an eight-pin connector would be the fourth twisted pair. Additionally, signal shielding was optimized by alternating the "live" and "earthy" pins of each pair. This pattern for the eight-pin connector results in a pinout where the outermost pair are then too far apart to meet the electrical requirements of high-speed LAN protocols. Two commonly used standard pinouts defined in TIA/EIA-568-B (T568A and T568B) overcome this by using adjacent pairs on the outer four pins. T568A and T568B differ by swapping the locations of the green and orange pairs, and thus have identical performance characteristics. A given location will generally standardize on one of the two options for consistency. Image File history File links Wire_white_green_stripe. ... Image File history File links Wire_white_orange_stripe. ... Image File history File links Description: DE: Pinbelegung RJ-45 Stecker EN: Pins of a RJ-45-jack Source/Drawer: Self made, 10:47, 5 August 2005 (UTC) License: GNU FDL --Rhododendronbusch 10:47, 5 August 2005 (UTC) File links The following pages link to this file: RJ-45 ... Image File history File links Wire_green. ... Image File history File links Wire_orange. ... Image File history File links Wire_white_orange_stripe. ... Image File history File links Wire_white_green_stripe. ... Image File history File links Wire_blue. ... Image File history File links Wire_blue. ... Image File history File links Wire_white_blue_stripe. ... Image File history File links Wire_white_blue_stripe. ... Image File history File links Wire_orange. ... Image File history File links Wire_green. ... Image File history File links Wire_white_brown_stripe. ... Image File history File links Wire_white_brown_stripe. ... Image File history File links Wire_brown. ... Image File history File links Wire_brown. ... RJ-11 is a physical interface often used for terminating twisted pair type cables. ... RJ stands for registered jack. ... 6p6c on cable, 6p4c socket RJ11 is a physical interface often used for terminating telephone wires. ... RJ48 (Registered Jack 48) is a telephone connector that has 8 positions. ... RJ-61 (Registered Jack 61) is a physical interface often used for terminating twisted pair type cables. ... Cat5 cables with RJ45 connectors wired to T568B TIA/EIA-568-B is a set of three standards that address commercial building cabling for telecommunications products and services. ...

Cables that are wired as T568A at one end and T568B at the other are known as "crossover" cables. Such cables often have orange sheaths and, before the widespread acceptance of auto-MDI/MDIX capabilities, were needed to connect hubs to routers. Abbreviated MDI, an Ethernet port connection that allows network hubs or switches to connect to other hubs or switches without a null-modem, or crossover cable. ... Medium dependent interface crossover or MDIX (the “X” representing “crossover”) is an Ethernet port connection that allows networked end stations (i. ...

Applications

A very common application is its use in Ethernet cables, where usually 8 pins (4 pairs) are used, e.g., a male-to-male cable to connect a cable or ADSL modem to the computer Ethernet network card. Ethernet is large and diverse family of frame-based computer networking technologies for local area networks (LANs). ... In electrical and mechanical trades and manufacturing, each of a pair of mating connectors or fasteners is conventionally assigned the designation male or female. ... Cable modem for broadband Internet access A cable modem is a special type of modem that is designed to modulate a data signal over cable television infrastructure. ... Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional modem can provide. ...

Other applications include other networking services such as ISDN and T1. A computer network is a system for communication between computers. ... Integrated Services Digital Network (ISDN) is a type of circuit switched telephone network system, designed to allow digital transmission of voice and data over ordinary telephone copper wires, resulting in better quality and higher speeds than available with analog systems. ... Two Network Interface Units, one with a single card, the other with two In telecommunications, T-carrier is the generic designator for any of several digitally multiplexed telecommunications carrier systems originally developed by Bell Labs and used in North America and Japan. ...

RJ45 is also used for RS-232 serial interface according to the EIA/TIA-561 standard[1] [2]. The pinout is described there. RS-232 (also referred to as EIA RS-232C or V.24) is a standard for serial binary data interchange between a DTE (Data terminal equipment) and a DCE (Data communication equipment). ...

See Registered jack for other, similar looking jacks, with which the RJ45 is likely (and often) confused. A registered jack (RJ) is a type of telephone jack. ...

In floodwired ¹ environments the center (blue) pair is often used to carry telephony signals. Where so wired, the physical layout of the RJ45 jack allows for the insertion of an RJ11 in the center of the socket, provided the RJ11 jack is wired to U.S. telephony standards using the center pair. The formal approach to connect telephony equipment is the insertion of a type-approved converter. In telecommunication, Telephony encompasses the general use of equipment to provide voice communication over distances. ... RJ-11 is a physical interface often used for terminating twisted pair type cables. ...

The remaining (brown) pair is increasingly used for Power over Ethernet (POE). Legacy equipment may conflict with this use as manufacturers used to short circuit unused pairs to reduce signal cross talk. Some routers/bridges/switches can be powered by the unused 4 lines — blues(+) and browns(-) — to carry current to the unit. Power over Ethernet or PoE technology describes any system to transmit electrical power, along with data, to remote devices over standard twisted-pair cable in an Ethernet network. ... For alternate meanings see Short circuit (disambiguation) A short circuit (sometimes known as simply a short) is a fault whereby electricity moves through a circuit in an unintended path, usually due to a connection forming where none was expected. ... Cross-Talk is the analogue or digital interference caused by two tracks of information placed too close together for the reading mechanism to discretely discern one entirely from the other. ...

Beware: Different manufacturers of RJ45 jacks arrange for the pins of the RJ45 socket to be linked to wire connectors (often IDC type terminals) that are in a different physical arrangement from that of other manufacturers: Thus, for example, if you are in the habit of connecting your white/orange wire to the "bottom right hand" IDC terminal, which links it to RJ45 pin 1, be aware that on jacks made by other manufacturers this terminal may instead connect to RJ45 pin 2 (or any other pin, for that matter).

See also

• Category 3 cable
• Category 5 cable
• Category 6 cable
• Category 7 cable
• Networking

Category 3 cable, commonly known as Cat-3, is an unshielded twisted pair (UTP) cable designed to reliably carry data up to 10 Mbit/s, with a possible bandwidth of 16 MHz. ... Category 5 cable, commonly known as Cat 5, is an unshielded twisted pair cable type designed for high signal integrity. ... Cat 6- Category - 6, (ANSI/TIA/EIA-568-B.2-1) is a cable standard for Gigabit Ethernet and other network protocols that is backward compatible with the Category 5/5e and Category 3 cable standards. ... Category 7 cable (CAT7), (ISO/IEC 11801:2002 category 7/class F), is a cable standard for Ultra Fast Ethernet and other interconnect technologies that can be made to be backwards compatible with traditional CAT5 and CAT6 Ethernet cable. ... A computer network is a system for communication between computers. ...

Notes

Note 1:   floodwire is a chiefly British term for installing communications cables in a massive fashion in anticipation of their eventual use.

External links

• How to wire a 10BaseT or 100BaseT connector with Category 5 cable and RJ45 connectors
• How to create your own Ethernet Cables
• Devices that use RJ45
• RJ45 pinout