Manual

Specifications C-3
RJ-45 Pinouts and Crossover Function
The Ethernet standard also specifies that each segment implement a crossover function to
connect the transmitter of one device to the receiver of a device at the other end, and vice-versa.
The crossover function may be implemented internally at the hub/switch, or externally, through
the twisted-pair media.
10/100 Straight-Through Pinouts
If the crossover function is implemented internally, the port is labeled MDI-X (Medium
Dependent Interface –Crossover). When an MDI-X port is connected to an MDI port, the
twisted pair media should be wired straight-through using the physical pinouts indicated in
Table C-2.
Table C-2
10/100 Pinouts Using Internal, Straight-Through Crossover
Pin Function Color Match Function Pin
1 TD+ White/Orange TD+ 1
2 TD- Orange/White TD- 2
3 RD+ White/Green RD+ 3
4 Blue/White 4
5 White/Blue 5
6 RD- Green/White RD- 6
7 White/Brown 7
8 Brown/White 8
Figure C-1 shows straight-through 10/100 connector wiring to be used when the crossover
function is implemented on board the hub/switch.
Figure C-1. 10/100 Straight-Through Wiring for RJ-45 Connector