Twisted Pair Cables - NETGEAR FS508 - Switch Installation Manual

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.
Figure 5-1 illustrates straight-through twisted pair cable.
1
Tx
2
A
3
Rx
6
Key:
A = Uplink or MDI port (as on a PC)
B = Normal or MDI-X port (as on a hub or switch)
1, 2, 3, 6 = Pin numbers
Figure 5-1. Straight-through twisted pair cable
Figure 5-2 illustrates crossover twisted pair cable.
1
Rx
2
B
3
Tx
6
Key:
B = Normal or MDI-X port (as on a hub or switch)
1, 2, 3, 6 = Pin numbers
Figure 5-2. Crossover twisted pair cable
Cabling Guidelines
Installation Guide for the Model FS508 Fast Ethernet Switch
1
Rx
2
B
3
Tx
6
736EA
1
Rx
2
B
3
Tx
6
737EA
C-3