RJ-45
The RJ-45 connector is commonly used for network cabling and for telephony
applications. It's also used for serial connections in special cases. Here's a
look at it:
Pinout for Ethernet
Although used for a variety of purposes, the RJ-45 connector is
probably most commonly used for 10Base-T and 100Base-TX Ethernet connections.
| Pin # |
Ethernet
10BASE-T
100BASE-TX |
EIA/TIA 568A |
EIA/TIA 568B or AT&T 258A |
|
1 |
Transmit + |
White with green strip |
White with orange stripe |
|
2 |
Transmit - |
Green with white stripe or solid green |
Orange with white stripe or solid orange |
|
3 |
Receive + |
White with orange stripe |
White with green stripe |
| 4 |
N/A |
Blue with
white stripe or solid blue |
Blue with
white stripe or solid blue |
| 5 |
N/A |
White with
blue stripe |
White with
blue stripe |
|
6 |
Receive - |
Orange with white stripe or solid orange |
Green with white stripe or solid green |
| 7 |
N/A |
White with
brown strip or solid brown |
White with
brown stripe |
| 8 |
N/A |
Brown with
white stripe or solid brown. |
Brown with
white stripe or solid brown |
Because only two pairs of wires in the eight-pin RJ-45 connector are used to
carry Ethernet signals, and both 10BASE-T and 100BASE-TX use the same pins, a
crossover cable made for one will also work with the other.
Also, please note that it is very important that a single pair be used for
pins 3 and 6. If one conductor from one pair is used for pin 3 and a conductor
from another pair is used for pin 6, performance will degrade. See the
following figure.
| 
