RJ45-RS232

      RJ11-RJ45

      USB-RJ45










RJ45 connector
RJ45 connector

RJ45


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

It is this standard that allows the connection to the Internet. This connector is physically compatible with the RJ11 connector if you use an adapter.

On a computer wiring RJ45 10 / 100 Mbit/s, only 4 pins 1-2 and 3-6 are used to convey information.
In 1000 Mbps (1Gbps) of transmission, the 8 pins of the plug are used.
Two RJ45 wiring standards are mainly common to wire catch : the standard T568A and T568B standard.
These standards are very similar only the pair 2 (orange, white-orange) and 3 (green, white-green) are changed.






internet port RJ45 to a laptop
internet port RJ45 to a laptop

Straight RJ45 :


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










Right T568A







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 BROWN 8 BROWN






Right T568B


rj45-straight-and-crossover.jpg
Schematic of wiring RJ45 straight and cross
RJ45 crossover, definition :
Crossover cable (marked CROSSOVER CABLE) is generally 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 BROWN 8 BROWN






T568A crossed







1 WHITE / GREEN 1 WHITE / ORANGE
2 GREEN 2 ORANGE
3 WHITE / ORANGE 3 WHITE / GREEN
4 BLUE 4 WHITE/BROWN
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 BROWN 8 BROWN




RJ45 connector
RJ45 connector

So for a binding cross :


Connections RJ45 of the transmitter and receiver are reversed :

The pair of transmission from one side is connected to the pins of reception on the other side.