Q: I`m trying to convert an existing ThinNet Ethernet local area network to Category 5 wiring between two computers in a home. The system ran fine before recabling. The same computers ran fine on Category 5 a month ago when a hub linked four computers. I installed the cable and terminated in a T568B configuration at either end. When we plugged in the new cabling, neither computer could find the other. Is a hub required to link these machines?
A: First of all, the use of crossover cables is not recommended by the Ethernet standard...and now that we have that out of the way, if you have each connector in the channel configured as a T568B and you are not using a hub, you are connecting transmit-pair to transmit-pair and receive-pair to receive-pair. The transmit-pair must always be connected to the receive-pair. Either add a hub or install a cross-over cable at one end of the channel. In the case of 10Base-T Ethernet, a crossover cable would have a T568B on one end and a T568A on the other. Be certain that you label this cable or you may spend a lot of time in the future locating where you have accidentally installed it.
Donna Ballast is a communications analyst at the University of Texas at Austin and a bicsi reg-istered communications distribution designer (rcdd). Questions can be sent to her at Cabling Installation & Maintenance or at PO Drawer 7580, the University of Texas, Austin, TX 78713; tel: (512) 471-0112, fax: (512) 471-8883, e-mail: email@example.com.