FS518T.Manual.FINAL 5/19/00 12:55 PM Page 41

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 C-1 illustrates straight-through twisted pair cable.

1

Tx

2

A

3

Rx

6

1

Rx

2

B

3

Tx

6

Key:

736EA

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 C-1. Straight-Through Twisted Pair Cable

Figure C-2 illustrates crossover twisted pair cable.

1

Rx

2

B

3

Tx

6

1

Rx

2

B

3

Tx

6

737EA

Key:

B = Normal or MDI-X port (as on a hub or switch) 1, 2, 3, 6 = Pin numbers

Figure C-2. Crossover Twisted Pair Cable

cabling guidelines

C-3

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NETGEAR FS518T manual Twisted Pair Cables, Figure C-1. Straight-Through Twisted Pair Cable