Straight-Through Wiring; Crossover Wiring; Table B-1 10/100Base-Tx Mdi-X And Mdi Port Pinouts; Figure B-2 Straight-Through Wiring - SMC Networks EZ Switch SMCGS8P-Smart Installation Manual

B
Cables

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

Pin
1 Receive Data plus (RD+)
and GND (Positive V
2 Receive Data minus (RD-) and
and GND (Positive V
3
Transmit Data plus (TD+)
and -48V feeding power (Negative V
6
Transmit Data minus (TD-)
and -48V feeding power (Negative V
4, 5, 7, 8 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 the switch, you can use either
straight-through or crossover cable to connect to any device type.)
You must connect all four wire pairs as shown in the following diagram to support
Gigabit Ethernet connections.
End A

Crossover Wiring

If the twisted-pair cable is to join two ports and either both ports are labeled with an
"X" (indicating MDI-X) or neither port is labeled with an "X" (which indicates MDI), a
crossover must be implemented in the wiring. (When auto-negotiation is enabled for
B-2
MDI 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
4
White/Blue Stripe
5
6
7
8
White/Brown Stripe

Figure B-2 Straight-through Wiring

MDI-X Signal Name
Transmit Data plus (TD+)
and -48V feeding power (Negative V
Transmit Data minus (TD-)
and -48V feeding power (Negative V
Receive Data plus (RD+)
) and GND (Positive V
port
Receive Data minus (RD-)
) and GND (Positive V
port
Not used
Orange
Blue
Green
Brown
)
port
)
port
)
port
)
port
1
2
End B
3
4
5
6
7
8