Q:What is the proper pairing of an Ethernet flip cable using T568B connectors? Is it a complete reversal of wires or just a reversal of pairs?

Dennis Horne

Complete Computing Inc.

Sherwood, AR

A:Reverse just the pairs. The following table shows the normal pin-outs of an Ethernet patch cord designed for using T568B connectors.

An Ethernet crossover patch cord can be used to cascade hubs or to connect two Ethernet stations back-to-back without a hub. If you have two personal computers you want networked to share resources--for example, printers or disk drives--and you want to do this without spending a lot of money, this configuration is for you. If your two PCs are running Windows for Workgroups, Windows 95, Windows NT, or any combination thereof, you can create a simple Ethernet network using only network interface cards. Here is how:

- Purchase two Ethernet cards for your PCs.

- Install the cards following the manufacturer`s instructions.

- Construct a null-crossover cable using the pin-outs in the following table.

- Connect the PCs by plugging the cross-over cable into the two Ethernet cards.

- Follow the instructions in Windows for Workgroups, Windows 95, or Windows NT for configuring a peer-to-peer network.

To construct an Ethernet crossover cable you will need two 8-pin modular plugs and a length of cable containing at least four conductors. Install the two plugs according to the pin-outs in the table. While there are other ways to do this, I recommend Ethernet so that when you need to connect additional PCs later on, the addition of a hub will allow you to grow your network.

Donna Ballast is a communications analyst at The University of Texas at Austin and a bicsi registered communications distribution designer (rcdd). Questions can be sent to her at Cabling Installation & Maintenance or at PO Drawer 7580, The University of Texas