Original subtitles

The gigabit Ethernet standard requires that all pins be connected.

So this is an example of a crossover cable for gigabit using the T568B standard.

Notice all pins are configured in a crossover fashion

all 4 pairs of wires are used in this example.

Now in the past you�d have to know when to use a straight through or crossover cable.

Any of these implementations would use a straight through cable.

So router to switch, PC to switch, PC to bridge or PC to hub.

Any of these implementations would use a crossover cable.

So router to router, switch to switch, PC to PC or hub to hub 10

or bridge to switch, PC to server, hub to switch and once again 11

router to router, all require crossover cables. 12

However today automatic crossover or auto MDIX is widely used. 13

Auto MDIX was introduced in 1998 14

and it made to the requirements for crossover cables obsolete 15

MDI devices are typically routers or PCs 16

MDIX devices are typically switches or hubs. 17

So they are Medium Dependent Interface crossover devices. 18

And in the past you would need to connect an MDI device 19

such as a PC to switch or hub. 20

In the old days once again, certain ports would have a button to flip the roll 21

from MDIX to MDI which would allow you to connect a switch to a switch 22

using a straight through cable. 23

However today in a lot of cases, auto MDI/MDIX 24

allows for automatic switching once the cable is connected. 25

The devices can auto detect the cable type 26

so there�s no need to worry as much about cable types today. 27

The straight through cable as an example 28

could be used between hubs or between switches. 29

So in the past, you used to have to use a crossover cable 30

between 2 switches but that�s not necessarily required today. 31

Straight through cables could be used 32

and devices would work out which side is MDI and which side is MDIX. 33

However be careful that�s not always true. 34

When on sites you may encounter an older Cisco switch 35

that doesn�t support auto MDI/MDIX. 36

So you may have to use the correct cabling type between all the devices.