As I am learning to crimp ethernet cables..

[frank84]

I googled it to research the diagram of wires...
and i get 2 diff diagram..

one for EIA/TIA 568A
and other one for EIA/TIA 568B

what's the difference??


-edit-
so I found out that... one of them is 'patch' and other one is 'cross over'

... is 'patch' cable regular ethernet cable that i would buy? or is it 'cross over'??

where do i use the cross over?

 

[tropic]

Actually, a crossover is a cable with one end wired to T-568A spec and the other to T-568B. A regular "patch" or "straight-through" cable has both ends wired to the same standard (A or B) but doesn't mix the two.

I normally use the T-568A standard because it's supposed to be more compatible for the phone guys. Modern switches don't care if you mix a bunch of A or B wired straight-through cables, and most recent ones don't care if they're straight-through or crossover--they'll sort it out themselves. Crossovers are normally used between nics or between older hubs/switches.

 

[imported_itr]

cross over is for switch/router connect to switch/router and computer connected to computer. patch is for computer connected to router/switch. sorry if i seem a little vague.

 

[Audiotherapy]

like devices : ie. router to router, switch to switch, NIC to NIC uses Crossover Cable
unlike devices: ie. router to switch, switch to NIC, NIC to Router uses Patch, straighthru cable

 

[frank84]

thanx everyone.. i got it now.

 

[Arch Enemy]

a straight through cable, like said above, is to connect say your computer to your router, a crossover cable is used to connect a pc to another pc, in order for networking to work, there has to be a crossover somewhere, in routers, hubs, switches ect has the crossover in the device, so if you want to connect two computers together and don't have a router or anything, you'll need to use a crossover cable for it to work.


EDIT: oops I typed that while you were posting I guess

 

[cmetz]

wonho84, EIA-568B is the US standard color-to-pin mapping, while EIA-568A is the European standard. You can use one or the other, either will result in the right pins being paired up for Ethernet 10/100/1000 signalling. But if you are in the USA, you should use the USA standard. And don't mix the two in your cable plant, consistency is the key to sanity.

A cross-over cable for 10BaseT or 100BaseT connects pins 1&2 (TX, 568B orange) to pins 3&6 (RX, 568B green) on the other end, and vice versa. If that happens to be achieved by mixing 568A on one end and 568B on the other, that's a convenient accident. I don't remember 568A enough to tell you if it works out. But it is not the definition or intent.

You use cross-over to connect two MDI devices together, or two MDI-X devices together. A station/NIC is typically a MDI device, and a switch or hub is typically a MDI-X device. Technically speaking, you need one cross-over to connect two 10BaseT/100BaseT systems. Normally, that cross-over is provided internally in the switch or hub, hence the X in MDI-X. But if you connect two switches together, you have two crosses, which cancel each other out, so a crossover cable gives you three crosses, or a net of one. If you connect two stations together, you have zero crosses, so a crossover cables gives you the necessary one.

 

[tw1164]

I use 568B, I think its easier to do.