B Cables
Table B-1 10/100BASE-TX MDI and MDI-X Port Pinouts
Pin | MDI Signal Name | MDI-X Signal Name |
1 | Transmit Data plus (TD+) | Receive Data plus (RD+) |
| | |
2 | Transmit Data minus (TD-) | Receive Data minus (RD-) |
| | |
3 | Receive Data plus (RD+) | Transmit Data plus (TD+) |
| | |
6 | Receive Data minus (RD-) | Transmit Data minus (TD-) |
| | |
4,5,7,8 | Not used | 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 these switches, 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.
EIA/TIA 568B RJ-45 Wiring Standard 10/100BASE-TX Straight-through Cable
| | White/Orange Stripe | |
| | Orange | |
| 1 | White/Green Stripe | 1 |
End A | 2 | | 2 |
| 3 | Blue | 3 |
| 4 | | 4 |
| 5 | White/Blue Stripe | 5 |
| 6 | Green | 6 |
| 7 | 7 |
| |
| 8 | White/Brown Stripe | 8 |
| | |
Brown
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 these switches, you can use either straight-through or crossover cable to connect to any device type.)
