67Table 29 RJ-45 MDI port pinouts10Base-T/100Base-TX 1000Base-TPinSignal Function Signal Function1 Tx+ Sends data BIDA+ Bi-directional datacable A+2 Tx- Sends data BIDA- Bi-directional datacable A-3 Rx+ Receives data BIDB+ Bi-directional datacable B+4 Reserved N/A BIDC+ Bi-directional datacable C+5 Reserved N/A BIDC- Bi-directional datacable C-6 Rx- Receives data BIDB- Bi-directional datacable B-7 Reserved N/A BIDD+ Bi-directional datacable D+8 Reserved N/A BIDD- Bi-directional datacable D-Table 30 RJ-45 MDIX port pinouts10Base-T/100Base-TX 1000Base-TPinSignal Function Signal Function1 Rx+ Receives data BIDB+ Bi-directional datacable B+2 Rx- Receives data BIDB- Bi-directional datacable B-3 Tx+ Sends data BIDA+ Bi-directional datacable A+4 Reserved N/A BIDD+ Bi-directional datacable D+5 Reserved N/A BIDD- Bi-directional datacable D-6 Tx- Sends data BIDA- Bi-directional datacable A-7 Reserved N/A BIDC+ Bi-directional datacable C+8 Reserved N/A BIDC- Bi-directional datacable C-To ensure normal communication, the pins for sending data on one port must correspond to the pins forreceiving data on the peer port. When both of the ports on the two devices are MDI or MDIX, use acrossover Ethernet cable; when one port is MDI and the other is MDIX, use a straight-through Ethernetcable. To summarize, straight-through and crossover cables connect the following devices:
