3com 10005622 Manual De Usuario

C

HAPTER

 3: C

ABLING

 S

WITCH

 3900 P

ORTS

Your Switch 3900 has 24 or 36 10/100BASE-TX ports 
with RJ-45 connectors. This section contains 
information on cabling the 10/100BASE-TX (RJ-45) 
ports and pin assignments for the RJ-45 connectors.

The Switch 3900 system’s Ethernet ports are shielded 
RJ-45 data sockets. You can connect shielded or 
unshielded data cables with shielded or unshielded 
jacks to these data sockets. 

The Ethernet ports are numbered from 1X to 24X or 
1X to 36X, depending on your system. They are 
configured as MDI-X for direct connection to a 
workstation or other data terminal equipment (DTE), 
using straight-through twisted-pair wiring.

To connect a Switch 3900 system to a 
10/100BASE-TX repeater or switch, use a crossover 
cable, or set the port on the connected device to MDI 
and use a straight-through cable. 

Follow these guidelines when you cable 
10/100BASE-TX connectors:

■

Use two twisted-pair wires for each link.

■

Use twisted-pair wire that is 22-26 AWG (0.5 
millimeter) in diameter.

■

Use twisted-pair wire with an impedance of 
between 85 and 115 Ohms. 

■

Verify that the length of the twisted-pair link from 
the system to any potential workstation location is 
100 meters (328 feet) or less.

To cable a 10/100BASE-TX (RJ-45) port:

Remove the dust cover and save it for future use.

Plug the male RJ-45 connector on the 
10/100BASE-TX cable into the selected port until it 
clicks into place.

Attach the other end of the cable to an MDI port on a 
workstation, repeater, or concentrator.

Repeat steps 2 and 3 for the remaining ports.