Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 57)

Getting Started
Software Reference for x310 Series Switches
C613-50046-01 REV A AlliedWare Plus TM Operating System - Version 5.4.4C 1.33
Trouble-shoot fiber and pluggable issues
Digital Diagnostics Monitoring (DDM) for SFP (1 Gigabit Small Form-factor Pluggable) and
SFP+ (10 Gigabit Small Form-factor Pluggable) transceivers allows you to measure optical
parameters for pluggables installed in a switch and trouble shoot fiber issues.
Fiber cable can be vulnerable to damage. Patch panels and patch cables can be connected
with the wrong type of fiber, fiber splices can become faulty and fiber cables can be cut
accidentally. Trouble shooting fiber issues has required special equipment and expertise
to find the source of a problem causing signal attenuation. Digital monitoring features
help find fiber issues.
Different types of transceivers are supported in different models of switch. See your Allied
Telesis dealer for more information about the particular models of pluggables that your
switch supports, and if these transceivers also support digital monitoring.
To display information about transceivers installed on your switch, enter the following
command:
The following parameters are measured and are displayed in show system pluggable
diagnostics command output:
■ Temperature (Centigrade) inside the transceiver
■ Vcc (Volts) voltage supplied to the transceiver
■ Tx Bias (mA) current to the Laser Diode in the transceiver
■ Tx Power (mW) the amount of light transmitted from the transceiver
■ Rx Power (mW) the amount of light received in the transceiver
You can track Tx Bias to find out how the Laser Diode in the transceiver is aging by
comparing the Tx Bias for one transceiver against Tx Bias for others. You can use this
information to see if any transceivers may need replacement.
You can trouble shoot fiber connectivity issues by checking the Tx Power at one end of the
fiber link against the Rx Power at the other end of the fiber link to measure the
attenuation. Knowing the attenuation enables you to determine if there are anomalies in
the fiber cable.
Note that Tx Power differences between the same type of transceivers installed on a
switch may indicate that a transceiver is not seated or locked. Ensuring transceivers are
seated and locked in place with the retaining clip will keep the fiber link up if there is any
vibration or movement that can dislodge a fiber cable. Rx Power differences may indicate
poor fiber patch cables, poor connectors or poor splices. Tracking Tx Bias for installed
transceivers and measuring attenuation for fiber links allows you to perform periodic
preventative maintenance, instead of reacting to a failure. Tracking Tx Power differences
can be used as an indicator of failure in an which may need replacing.
awplus# show system pluggable diagnostics