RJ Standards


RJ ... 'Registered Jack', telephone connection interfaces, registered with the FCC, the U.S. Federal Communications Commission. Their history goes back to the Bell System and AT&T's Universal Service Order Codes (USOC) in the 70s. These were adopted later as part of the FCC regulations.

Registered Jack
Width (Positions)
Pins Installed
Installed Pins
  
RJ-10
4
Position
4 Installed
1,2,3,4
 telephone, data
RJ-11
6
Position
4 Installed
2,3,4,5
 standard telephone connection, data
RJ-12
6
Position
6 Installed
1,2,3,4,5,6
 telephone, data
RJ-14
6
Position
4 Installed
2,3,4,5
 connection for 2 analog phone lines
RJ-45
8
Position
8 Installed
1,2,3,4,5,6,7,8
 ISDN, LAN, data
RJ-48
10
Position
8, 10 Installed
1,2,3,4,5,6,7,8, 9,10
 DATA

The RJ48 has an extra tab so that a RJ48 plug will not push into a RJ45 jack, but a RJ45 plug will mate with a RJ48 jack.




Ethernet Pinout
RJ 45 Pin

1 2 3 4 5 6 7 8

Pair

3 T 3 R 2 T 1 R 1 T 2 R 4 T 4 R

Color Code EIA/TIA-568-A

wt/gn gn wt/or bl wt/bl or wt/br br

 

RecvData+ RecvData- TxData +     TxData -    

Color Code EIA/TIA-568-B

wt/or or wt/gn bl wt/bl gn wt/br br

 

TxData + TxData - RecvData+     RecvData-    


Ethernet 10/100Base-T uses only pair 3 and pair 2.




ISDN BRI RJ45 Standard
RJ 45 Pin

1 2 3 4 5 6 7 8

Pair

Tx+ Rx + Rx - Tx -