And when do you use a crossover cable and a straight thru cable?
2006-07-06 14:45:54 · 1 answers · asked by chris B 3 in Computers & Internet ➔ Computer Networking
MDI = Medium Dependent Interface and MDI-X = Medium Dependent Interface Crossed. Two different devices like a PC and a switch must use a straight through cable, and two similar devices such as connecting 2 PCs together or daisy chaining 2 switches must use a crossover cable.
RJ-45 jacks and cables only use 4 of the 8 wires, they use pins 1,2,3 and 6. On an MDI interface (switches) pins 1/2 are transmit plus and transmit minus, and pins 3/6 are receive plus and minus. On an MDI-X interface (computers/NICs) pins 1/2 are receive plus/minus and pins 3/6 are transmit plus/minus.
On many newer switches, you don't even have to worry about the cabling because they use automatic MDI/MDI-X detection. So be careful not to be fooled into thinking "you definitely needed a crossover" just because you plugged one in and it worked, because the switch may have fixed it for you automatically.
2006-07-06 16:15:57 · answer #1 · answered by networkmaster 5 · 0⤊ 0⤋