Allied Telesis AlliedWare Plus x950 Series Installation Manual page 200

Chapter 13: Troubleshooting
200
Problem 3: A 1Gbps or 10Gbps fiber optic transceiver in a base port
(ports 1 to 24) is unable to establish a link to a network device.
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 to Problem 3.

Use the SHOW PLATFORM command to confirm that the port is
configured correctly for the transceiver. If necessary, use the
PLATFORM PORTMODE INTERFACE command to configure the
port. For more information, refer to "PLATFORM PORTMODE
INTERFACE" on page 134. 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.