Crossover cable
termnetworkingIT support
Stands for: Crossover cable (MDI/MDI-X)
A patch cord wired T568A on one end and T568B on the other - once required to connect like devices, now made obsolete by auto-MDIX.
Ethernet's transmit and receive pairs had to line up: connecting a PC to a switch used a straight-through cable, but PC-to-PC or switch-to-switch needed the pairs crossed. Gigabit-era auto-MDIX let ports detect and swap electronically, so any modern port pair works with any cable. The crossover survives as a toolbox relic, a lab trick for ancient gear, and a recurring exam question.
Also known as: crossover, mdi-x, auto-mdix, straight-through