RJ45 | Technical Characteristics | instrumentic.info

Connector RJ45
Connector RJ45

RJ45

This is the network standard that allows internet connection. This type of cable has 8 electrical connection pins. It is also called ETHERNET cable or 8P8C connector (8 positions and 8 electrical contacts).


It is this standard that allows internet connection. This connector is physically compatible with the RJ11 connector if using an adapter.

On 10/100 Mbps RJ45 computer wiring, only 4 1~2 and 3~6 pins are used to transmit information.
In 1000 Mbps (1Gbps) transmission, the 8 socket pins are used.
Two RJ45 wiring standards are mainly common to wire the sockets : T568A and T568B.
These standards are very similar : only pairs 2 (orange, white~orange) and 3 (green, white~green) are changed.

RJ45 internet port of a laptop
RJ45 internet port of a laptop

RJ45 right :

The right cable (marked PATCH CABLE or STRAIGHT~THROUGH CABLE) is used to connect a device to a network hub or network switch.

T568A right

1 WHITE/ GREEN 1 WHITE / GREEN
2 GREEN 2 GREEN
3 WHITE / ORANGE 3 WHITE / ORANGE
4 BLUE 4 BLUE
5 WHITE/BLUE 5 WHITE/ BLUE
6 ORANGE 6 ORANGE
7 WHITE/BROWN 7 WHITE / BROWN
8 MARRON 8 MARRON

RJ45 wiring scheme straight and crossed
RJ45 wiring scheme straight and crossed

T568B right

RJ45 cross, definition :
The crossover cable (marked CROSSOVER CABLE) is usually used to connect two hubs or network switches.

1 WHITE / ORANGE 1 WHITE / ORANGE
2 ORANGE 2 ORANGE
3 WHITE / GREEN 3 WHITE / GREEN
4 BLUE 4 BLUE
5 WHITE/BLUE 5 WHITE/ BLUE
6 GREEN 6 GREEN
7 WHITE/BROWN 7 WHITE / BROWN
8 MARRON 8 MARRON

T568A crossed

1 WHITE / GREEN 1 WHITE / ORANGE
2 GREEN 2 ORANGE
3 WHITE/ ORANGE 3 WHITE / GREEN
4 BLUE 4 WHITE/MARRON
5 WHITE/BLUE 5 BROWN
6 ORANGE 6 GREEN
7 WHITE/BROWN 7 BLUE
8 BROWN 8 WHITE / BLUE

T568B crossed

1 WHITE / GREEN 1 WHITE / ORANGE
2 GREEN 2 ORANGE
3 WHITE/ ORANGE 3 WHITE / GREEN
4 BLUE 4 BLUE
5 WHITE/BLUE 5 WHITE/ BLUE
6 ORANGE 6 GREEN
7 WHITE/BROWN 7 WHITE / BROWN
8 MARRON 8 MARRON

Connector RJ45
Connector RJ45

So for a cross~link :

The rJ45 links of the transmitter and receiver are reversed :

The transmission pair on one side is connected to the receiving pins on the other side.