NETGEAR DG814 DSL manual Cable Quality

Reference Manual for the Model DG814 DSL Modem Internet Gateway

•Crossover cable

A crossover cable is a special cable in which the transmit and receive pairs are exchanged at one of the two cable connectors. Crossover cables are often unmarked as such, and must be identified by comparing the two connectors. Since the cable connectors are clear plastic, it is easy to place them side by side and view the order of the wire colors on each. On a straight-through cable, the color order will be the same on both connectors. On a crossover cable, the orange and blue pairs will be exchanged from one connector to the other.

•Auto MDI/MDI-X switching

Some Ethernet switch products, such as the Model DG814 gateway, are able to sense the polarity of a connection and automatically adapt to the proper mating polarity.

Cable Quality

A twisted pair Ethernet network operating at 10 Mbits/second (10BASE-T) will often tolerate low quality cables, but at 100 Mbits/second (10BASE-Tx) the cable must be rated as Category 5, or "Cat 5", by the Electronic Industry Association (EIA). This rating will be printed on the cable jacket. A Category 5 cable will meet specified requirements regarding loss and crosstalk. In addition, there are restrictions on maximum cable length for both 10 and 100 Mbits/second networks.

B-12 Networks and Routing Basics