Allied Telesis x950 Series Installation Manual page 158

Chapter 11: Troubleshooting
158
Solutions: Try the following:
Check that the transceiver is fully inserted in the port.

Verify that the fiber optic cable is securely connected to the port on

the transceiver and the remote network device.
Verify that the remote network device is operating properly.

Verify that the operating specifications of the fiber optic ports on

the transceiver and remote network device are compatible.
Verify that the correct type of fiber optic cabling is being used.

Verify that the port is connected to the correct fiber optic cable.

Try connecting another network device to the fiber optic port using

a different cable. If the port is able to establish a link, then the
problem is with the cable or with the other network device.
Use the switch's management software to verify that the port is

enabled.
If the remote network device is a managed device, use its

management firmware to determine whether its port is enabled.
If the problem is with two BiDi (bi-directional) transceivers, refer to

their data sheets to verify that their transmission and reception
frequencies are opposite each other. For instance, a BiDi
transceiver that transmits and receives at 1310nm and 1550nm,
respectively, has to be connected to a transceiver that transmits
and receives at 1550nm and 1310nm, respectively. Two BiDi
transceivers will not establish a link if they transmit and receive at
the same frequencies.
Test the attenuation of both directions on the fiber optic cable with

a fiber optic tester to determine whether the optical signal is too
weak or strong.
Problem 4: A 40Gbps or 100Gbps fiber optic transceiver in port 25, 29,
33, or 37 cannot establish a link with a network device.
Solutions: Try the following:
Review the solutions in Problem 3.

Use the SHOW PLATFORM command to confirm that the port is

configured correctly for an 100Gbps fiber optic transceiver. If
necessary, perform "Configuring Ports 25 to 37" on page 125.
Changing a port from a 40Gbps transceiver or breakout cable to a
100Gbps transceiver requires resetting the switch. The same is
also true when replacing a 100Gbps transceiver with a 40Gbps
transceiver or breakout cable.
If the problem is with an 100Gbps transceiver, you might need to

adjust the Forward Error Correction (FEC) parameter on the port,
with the FEC command. Refer to the Software Reference for x950