Port and Cable Assignments

11

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.
Crossover Wiring
If the twisted-pair cable is to join two ports and either 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.
Straight-Through RJ-45 Pin Assignments
End 1 End 2
1 (RD+) 1 (TD+)
2 (RD-) 2 (TD-)
3 (TD+) 3 (R D+)
6 (TD-) 6 (RD-)
Crossover RJ-45 Pin Assignments
End 1 End 2
1 (TD+) 3 (R D+)
2 (TD-) 6 (RD-)
3 (RD+) 1 (TD+)
6 (RD-) 2 (TD-)