EIA-TIA Cabling Specifications

The ANSI/EIA/TIA-568-1991 Standard Commercial Building Telecommunications Wiring Standard defines the following pinouts:

Standard EIA/TIA T568A (also called ISDN, previously called EIA)

/--T3  1    White/Green
Pair3 \--R3  2    Green
/----------T2  3   White/Orange
/         /-R1  4   Blue
pair2 \   pair1 \-T1  5   White/Blue
\----------R2  6   Orange
/--T4  7   White/Brown
pair4 \--R4  8   Brown

Standard EIA/TIA T568B (also called AT specification, previously called 258A)

/--T2  1   White/Orange
pair2 \--R2  2   Orange
/----------T3  3   White/Green
/         /-R1  4   Blue
pair3 \   pair1 \-T1  5   White/Blue
\----------R3  6   Green
/--T4  7   White/Brown
pair4 \--R4  8   Brown

USOC (Universal Service Order Code)

8-pins  6-pins
|  |
/-------------T4  1     White/Brown
/    /---------T3  2  1  White/Green
/    /    /-----T2  3  2  White/Orange
/    /    /    /-R1  4  3  Blue
pr4\ pr3\ pr2\ pr1\-T1  5  4  White/Blue
\    \    \-----R2  6  5  Orange
\    \---------R3  7  6  Green
\-------------R4  8     Brown

Plug Orientation:

The EIA/TIA specifies an RJ-45 (ISO 8877) connector for Unshielded Twisted Pair (UTP) cable. The plug is the male component crimped on the end of
the cable while the jack is the female component in a wall plate or patch panel, etc. Here is the pin numbering to answer the question, where is pin one?

Plug                                                Jack
(Looking at connector                         (Looking at cavity
end with the cable                                 in the wall)
running away from you)

---------- /              ----------
| 87654321 |              | 12345678 |
|__      __|/             |/_      /_|
|____|                    |/___|

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