Allied Telesis AT-8012M Installation Manual page 76

Troubleshooting
76
For twisted pair ports, verify that the LINK LED for each port is ON. If a
Link LED is OFF, do the following:
Verify that the end-node connected to the port is powered ON
and is operating properly.
Check that the twisted pair cable is securely connected to the port
on the switch and to the port on the end-node.
Make sure that the twisted pair cable does not exceed 100 m
(328 ft).
Verify that you are using the appropriate category of twisted pair
cable: Category 3 or better for 10 Mbps operation and Category 5
and Category 5E for 100 Mbps and 1000 Mbps operations.
Make sure that the operating parameters of the port on the switch
are compatible with the end-node to which the port is connected.
This will require using the switch's management software. For
instructions, refer to the AT-S39 Management Software User's
Guide.
For fiber optic ports, verify that the LINK LED for each port is ON. If a LINK
LED is OFF, do the following:
Verify that the end-node connected to the port is powered ON
and is operating properly.
Check that the fiber optic cable is securely connected to the port
on the switch and to the port on the end-node.
ST and SC ports consist of two separate connectors, as shown in
Figure 33 on page 65. Each connects to a separate fiber strand.
One is for receiving data and the other is for transmitting data.
When connecting a fiber optic cable to a ST or SC port, be sure
that the receiver fiber connector is connected to the transmitter
connector on the remote end-node, and the transmitter fiber
connector is connected to the receiver connector on the remote
node.
Make sure that you are using the appropriate type of fiber optic
cable and that the cable length does not exceed the allowed
maximum distance. For an AT-8000 Series Switch, refer to
"Planning the Installation" on page 50. For an optional GBIC
module, refer to the GBIC Installation Guide. For an optional
fiber optic expansion module, refer to the Expansion Module
Installation Guide.