A crossover cable is a segment of Category 5 (5e) cable that crosses over pins 1&2 and pins 3&6. This cable is normally used to connect two PCs (Peer to Peer) without the use of a hub/switch or router. One cable hooks directly into the back of both computers using a standard Ethernet Network Interface (NIC) card with RJ45 ports.

In effect, the crossover cable will be terminated to EIA / TIA 568B at one end and EIA / TIA 568A at the other, exactly as shown in the two color coded plugs as shown below. For standard patch cable wiring you just wire both ends terminated to EIA / TIA 568A (left schematic) on both ends.

	REMEMBER To hold the RJ45 connector with the 'clip' on the bottom. To have to the 'opening' (where you insert the cable) facing you.
EIA / TIA 568A		EIA / TIA 568B

Straight-Through vs. Cross-Over

In general, the patch cords that you use with your Ethernet connections are "straight-through", which means that pin 1 of the plug on one end is connected to pin 1 of the plug on the other end. In this particular case it is not then important to wire them as above. Pin 1 is Pin 1 etc etc. However for the sake of uniformity it may be best to wire your cables with the same color sequence. Cross-Over cables are "crossed" end to end and data cables aren't. If you have a network hub/switch that has an uplink port on it then you do not need to make or purchase a cross-over cable. Just switch the port on the hub/switch to the 'uplink' mode if need be. If your hub/switch does not have an 'uplink' port on it then the only way to cascade another hub or attach a cable modem is to use a cross-over cable. It helps for future reference to mark or attach a tag to the cross-over cable so that you do not attempt to use it as a 'normal' patch lead at some time in the future.

REMEMBER To hold the RJ45 connector with the 'clip' on the bottom. To have to the 'opening' (where you insert the cable) facing you.

The only time you cross connections with Category 5 patch cable is when you connect two Ethernet devices directly together without a hub. This can be two computers connected without a hub, two hubs via standard Ethernet ports in the hubs, or in rare cases broadband modems. If you are not sure consult your products user manual, or your ISP. Then you need a "cross-over" patch cable, which crosses the transmit and receive pairs, the orange and green pairs in normal wiring. In a cross-over cable, one end is normal, and the other end has the cross-over configuration. Remember you can only network two computers together with Cat5 cable. To add extra PC's to your network you will require a hub or a switch.

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