Table B-1. 10/100BASE-TX MDI and MDI-X Port Pinouts
Pin | MDI Signal Name | MDI-X Signal Name |
1 | Transmit Data plus (TD+) | Receive Data plus (RD+) |
2 | Transmit Data minus (TD-) | Receive Data minus (RD-) |
3 | Receive Data plus (RD+) | Transmit Data plus (TD+) |
6 | Receive Data minus (RD-) | Transmit Data minus (TD-) |
4,5,7,8 | Not used | Not used |
Note: The “+” and “-” signs represent the polarity of the wires that make up each wire pair.
Straight-Through Wiring
If the twisted-pair cable is to join two ports and only one of the ports has an internal crossover (MDI-X), the two pairs of wires must be straight-through. (When auto-negotiation is enabled for any RJ-45 port on this switch, you can use either straight-through or crossover cable to connect to any device type.)
Crossover Wiring
If the twisted-pair cable is to join two ports and both ports are labeled with an “X” (MDI-X) or neither port is labeled with an “X” (MDI), a crossover must be implemented in the wiring. (When auto-negotiation is enabled for any RJ-45 port on this switch, you can use either straight-through or crossover cable to connect to any device type.)