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Cabling Characteristics
4.4 Straight-Through Wiring
If the twisted pair link segment is to connect two
ports and only one of the ports features an internal
crossover, the two pairs of wires must be straight-
through:
STRAIGHT-THROUGH RJ-45 PIN ASSIGNMENTS
(8-pin RJ-45)
(10-pin RJ-45)
Concentrator
Device
Concentrator
Device
X
1 (Rx+)
1 (Tx+)
2 (Rx+)
2 (Tx+)
2 (Rx-)
2 (Tx-)
3 (Rx-)
3 (Tx-)
3 (Tx+)
3 (Rx+)
4 (Tx+)
4 (Rx+)
6 (Tx-)
6 (Rx-)
7 (Tx-)
7 (Rx-)
4.5 Crossover Wiring
If both ports are labelled “X”, or neither port is
labelled, then the crossover must be implemented in
the wiring
(NOT X)
1 (+)
1 (+)
2 (+)
2 (+)
2 (-)
2 (-)
3 (-)
3 (-)
3 (+)
3 (+)
4 (+)
4 (+)
6 (-)
6 (-)
7 (-)
7 (-)
