Netgear FVL328 参照マニュアル

B-12

Networks, Routing, and Firewall Basics

10 ft. (3 m) from the wall outlet to the desktop device

The patch panel and other connecting hardware must meet the requirements for 100 Mbps 
operation (Category 5). Only 0.5 inch (1.5 cm) of untwist in the wire pair is allowed at any 
termination point.

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.

For two devices to communicate, the transmitter of each device must be connected to the receiver 
of the other device. The crossover function is usually implemented internally as part of the 
circuitry in the device. Computers and workstation adapter cards are usually media-dependent 
interface ports, called MDI or uplink ports. Most repeaters and switch ports are configured as 
media-dependent interfaces with built-in crossover ports, called MDI-X or normal ports.  Auto 
Uplink technology automatically senses which connection, MDI or MDI-X, is needed and makes 
the right connection.

 illustrates crossover twisted pair cable.