SQID RJ-45 Connector and Pinouts

Pin	In	Out	Color
	Standard pinout (NIC=MDI)	Crossover pinout (HUB=MDI-X)	100BaseT Cable
1	Transmit +	Receive +	orange/white
2	Transmit -	Receive -	orange
3	Receive +	Transmit +	green/white
4	UUP1 +	UUP1 +	blue
5	UUP1 -	UUP1 -	blue/white
6	Receive -	Transmit -	green
7	UUP2 +	UUP2 +	brown/white
8	UUP2 -	UUP2 -	brown
-	SHLD	SHLD

UUP1 and UUP2 are "unused pair" 1 and 2. When using a standard CAT5 cable, these pairs are connected to the two unused pairs in the 4 pair (8 wire) cable.

NOTE: Standard CAT5 design practice is to terminate these pairs on the PCB to reduce noise. When using a 2 pair cable, these pins are left unconnected in the cable.