A crossover cable reverses the transmit and receive pin pairs between its ends. It lets devices that transmit on the same pins communicate, such as two routers, switches, or PCs. section 3.3.2
Pins 1–2 on one end connect to pins 3–6 on the other. A straight-through cable connects matching pairs, so same-type devices cannot communicate without crossover wiring. section 3.3.2
Remember these practical points:
- Use a crossover cable when both connected devices transmit on the same pin pair. section 3.3.2
- Modern equipment often uses Auto MDI-X to adjust transmit and receive pins automatically. section 3.3.2
