Straight-Through Wiring; Crossover Wiring; Table B-1. 10/100Base-Tx Mdi And Mdi-X Port Pinouts; Figure B-2. Straight-Through Wiring - Enterasys V2H124-24P Hardware Installation Manual

B
Cables

Table B-1. 10/100BASE-TX MDI and MDI-X Port Pinouts

Pin
1 Receive Data plus (RD+)
2 Receive Data minus (RD-)
Transmit Data plus (TD+)
3
GND (Positive V
4
GND (Positive V
5
Transmit Data minus (TD-)
6
-48V feeding power (Negative V
7
-48V feeding power (Negative V
8
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.)
End A

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. (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.)
B-2
MDI-X Signal Name
)
port
)
port
EIA/TIA 568B RJ-45 Wiring Standard
10/100BASE-TX Straight-through Cable
White/Orange Stripe
White/Green Stripe
1
2
3
White/Blue Stripe
4
5
6
7
White/Brown Stripe
8
Brown Stripe

Figure B-2. Straight-through Wiring

MDI Signal Name
Transmit Data plus (TD+)
Transmit Data minus (TD-)
Receive Data plus (RD+)
GND (Positive V
GND (Positive V
Receive Data minus (RD-)
) -48V feeding power (Negative V
port
) -48V feeding power (Negative V
port
Orange
Blue
Green
)
port
)
port
)
port
)
port
1
2
End B
3
4
5
6
7
8