Installation Guide for the Model FE104 and Model FE108 Fast Ethernet Hubs
C-4
Fast Ethernet and Cabling Guidelines
Twisted Pair Cables
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. Refer to
the instructions in Chapter 3, “Installation,” for appropriate cable use and connection.
Figure C-1 illustrates straight-through twisted pair cable connections, and Figure C-2 illustrates
crossover twisted pair cable connections.
Key:
1 = Uplink or MDI port
2 = Normal or MDI-X port
Figure C-1.
Straight-through twisted pair cable
Key:
1 = Normal or MDI-X port
2 = Normal or MDI-X port
Figure C-2.
Crossover twisted pair cable
7181
Tx
Rx
1
2
1
3
6
Tx
Rx
1
2
3
6
2
7182
1
2
3
6
1
2
3
6
Tx
Rx
1
Tx
Rx
2
