Difference between revisions of "Ethernet RJ45 Wiring Reference"

Revision as of 11:55, 9 August 2008

TWISTED PAIR ETHERNET WITH RJ-45 CONNECTOR

If you hold the RJ-45 connector facing you (as if you were going to plug it into your mouth) with the lock tab down, then the pins are numbered 1 to 8 from left to right. The pin usage is as follows:

       Pin Number              Assignment
       ----------              ----------
       8                       Reserved for Telephone use
       7                       Reserved for Telephone use
       6                       Input Data (-)
       5                       Reserved for Telephone use
       4                       Reserved for Telephone use
       3                       Input Data (+)
       2                       Output Data (-)
       1                       Output Data (+)

* since it is best to think of the lock tab as always facing down, we put the above pin listing in descending order.

CLIP FACING DOWN - This is how I wire the connector on twisted pair ethernet: Three (3) and six (6) must be a twisted pair.

 T568B RJ 45 Std                     Cross Over Cable        T568-A RJ 45 (less common)
 ---------------                     ---------------         ---------------
 1. White Orange                     1. White Green          1. White Green
 2. Orange                           2. Green                2. Green
 3. White Green    (twisted pair)    3. White Orange         3. White Orange
 4. Blue                             4. White Brown          4. Blue
 5. White Blue                       5. Brown                5. White Blue
 6. Green          (twisted pair)    6. Orange               6. Orange
 7. White Brown                      7. Blue                 7. White Brown
 8. Brown                            8. White Blue           8. Brown