B Cables
Table B-1. 10/100BASE-TX MDI and MDI-X Port Pinouts
Pin | MDI-X Signal Name | MDI Signal Name |
1 | Receive Data plus (RD+) | Transmit Data plus (TD+) |
| | |
2 | Receive Data minus (RD-) | Transmit Data minus (TD-) |
| | |
3 | Transmit Data plus (TD+) | Receive Data plus (RD+) |
| | |
4 | GND (Positive Vport) | GND (Positive Vport) |
5 | GND (Positive Vport) | GND (Positive Vport) |
6 | Transmit Data minus (TD-) | Receive Data minus (RD-) |
| | |
7 | -48V feeding power (Negative Vport) | -48V feeding power (Negative Vport) |
8 | -48V feeding power (Negative Vport) | -48V feeding power (Negative Vport) |
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.)
EIA/TIA 568B RJ-45 Wiring Standard 10/100BASE-TX Straight-through Cable
| | White/Orange Stripe | | |
| | Orange | | |
End A | 1 | White/Green Stripe | 1 | |
2 | Blue | 2 | End B |
| 3 | | 3 | |
| 4 | White/Blue Stripe | 4 | |
| 5 | | 5 | |
| 6 | Green | 6 | |
| 7 | 7 | |
| | |
| 8 | White/Brown Stripe | 8 | |
Brown Stripe
Figure B-2. Straight-through Wiring
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.)
