Filter
Top Products
Model FS516/FS524 Fast Ethernet Switch Installation Guide
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. Most ports on
switches and repeaters have media-dependent interfaces with crossover ports.
These ports are referred to as MDI-X or normal ports. Computer and
workstation adapter cards are usually media-dependent interface ports referred
to as MDI or uplink ports.
These two figures illustrate the use of straight-through and crossover twisted
pair cables.
RJ-45 Connector
The RJ-45 connector (shown in the illustration with an RJ-45 plug) is used to
connect workstations, hubs, and switches through unshielded twisted pair cable.
The RJ-45 connector accepts four-pair Category 3 or Category 5 UTP cable.
RJ-45
Connector
Pin
Assignment
Normal Assignment
on Ports 1–8,
1–16, or 1–24
Uplink Assignment
on Port 8, 16, or 24
1 Input Receive Data + Output Transmit Data +
2 Input Receive Data - Output Transmit Data -
3 Output Transmit Data + Input Receive Data +
6 Output Transmit Data - Input Receive Data -
4, 5, 7, 8 Not used Not used
Straight-through
twisted pair cable
Crossover
twisted pair cable
8146EC
Tx
Uplink or
MDI port
Normal or
MDI-X port
Normal or
MDI-X port
Normal or
MDI-X port
Rx
1
2
3
6
Tx
Rx
1
2
3
6
1
2
3
6
1
2
3
6
Tx
Rx
Tx
Rx
711EA
18
12345678