Question : Cross Over Wire

What Is Cross Over Wire ?
How To Create It?
Whats Different Color Combinations Used In Making Cross Over wire?
Where That Cross Over Wire Used?
What Are Different Names Of Cross Over Wire.
Give Me The Complete Information About Cross Over Wire.
PLease Please Please?

Answer : Cross Over Wire

What Is Cross Over Wire ?

Answer:  Devices on a network (nodes) use different pins in their network interfaces to transmit and to receive by generating electrical signals which mean 1 or 0 on those wires depending on a common encoding scheme.  So, a node will transmit a signal meaning 1 down the appropriate wire.  In order for the node on the other end of the wire to receive that signal, it must come in on the wire in contact with its receive pin.  Therefore, a tranmsit (tx) goes to an receive (rx) and vice versa. This is commonly set up in a Data Terminal Equipment (DTE) and a Data Communication Equipment (DCE) such as a PC to a Switch.

In situations where you are using two of the same type of equipment - such as a PC to a PC - you're using a DTE to a DTE and their pins are the same on both sides - such as TX / RX  and TX / RX.  In this case, you have a TX talking to a TX and they'll both jam each other's signals with their transmissions and you have a RX listening to another RX and they won't hear anything.

So, in the case above, you need a "cross over cable" to cross the RX over to the TX and vice versa.

How To Create It?

Answer:  The easiest way is to buy one.  However, by asking these questions, I'll assume you want to make one.  In order to make a cable, you need some RJ-45 jacks and a crimper.  A nice wire cutter and stripper help, but are not necessary since you can do it with scissors.

Most patch cables you will look at are what is known as 568-B.  The easiest way for me is to simply switch the oranges and the greens which turns one end into a 568-A pinout and the other side stays 568-B.  The 568's refer to the specifications from the EIA /TIA.

Whats Different Color Combinations Used In Making Cross Over wire?

Answer:  If you're looking at a cable which is a 568-B pinout, "reading" from left to right:

1 White with Orange
2 Orange
3 White with Green
4 Blue
5 White with Blue
6 Green
7 White with Brown
8 Brown

To make a cross over, you would swap pins 1 to 3 and 2 to 6 - or White with Orange swaps with White with Green and Orange swaps with Green.

Where That Cross Over Wire Used?

Answer:  Cross over cables are mostly used when connecting like devices - such as switch to switch, pc to pc.  Rarely, you might need one connecting a DSL modem to a PC.  Many devices will have a little button labled mdi/mdix or "uplink/normal" - this little button will electrically swap the connections changing the port from a DCE to a DTE or vice versa.  Newer equipment may have this ability built into the port to automatically sense the "mismatch" and automatically swap the electrical connections for you without needing special cabling to do it manually.

What Are Different Names Of Cross Over Wire.

Cross over cable.  Roll over cable (although there are some roll over cables which totally reverse the pinout from one end to the other Pin 1 to 8, 2 to 7, 3 to 6, 4 to 5).  Cross connect cable.

Give Me The Complete Information About Cross Over Wire.

Answer - see above.  The others provided some excellent links.  These are very easy to find on the web.  See this for more info:  http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=crossover+pinout&spell=1

HTH