• Support
  • Articles
  • Resources
  • Products

RJ45 Wiring Standards

T568A and T568B are the two color codes used for wiring eight-position RJ45 modular plugs. Both are allowed under the ANSI/TIA/EIA wiring standards. The only difference between the two color codes is that the orange and green pairs are interchanged. T568A wiring pattern is recognized as the preferred wiring pattern for this standard because it provides backward compatibility to both one pair and two pair USOC wiring schemes. The T568B standard matches the older ATA&T 258A color code and is/was(?) the most widely used wiring scheme. It is also permitted by the ANSI/TIA/EIA standard, but it provides only a single pair backward compatibility to the USOC wiring scheme.

T568A Wiring Standard
Pin # 1 2 3 4 5 6 7 8
 Wire Color  RJ45 Wiring RJ45 Wiring RJ45 Wiring RJ45 Wiring RJ45 Wiring RJ45 Wiring RJ45 Wiring RJ45 Wiring
T568B Wiring Standard
Pin # 1 2 3 4 5 6 7 8
 Wire Color  RJ45 Wiring RJ45 Wiring RJ45 Wiring RJ45 Wiring RJ45 Wiring RJ45 Wiring RJ45 Wiring RJ45 Wiring
RJ45 to RJ45 Cable Pinouts
Straight Through Cable
RJ45   RJ45
Pin # Connects To Pin #
1 <--------> 1
2 <--------> 2
3 <--------> 3
4 <--------> 4
5 <--------> 5
6 <--------> 6
7 <--------> 7
8 <--------> 8
 
Crossover Cable
RJ45 RJ45
Pin # Connects To Pin #
1 <--------> 3
2 <--------> 6
3 <--------> 1
4 <--------> 7
5 <--------> 8
6 <--------> 2
7 <--------> 4
8 <--------> 5
 
Rollover Cable
RJ45   RJ45
Pin # Connects To Pin #
1 <--------> 8
2 <--------> 7
3 <--------> 6
4 <--------> 5
5 <--------> 4
6 <--------> 3
7 <--------> 2
8 <--------> 1