Ethernet Switching
Ethernet Switching

optics

‎05-27-2020 02:37 AM

hi

For troubleshooting perspective, which information in diagnostic optics is a key/standout between 2 interfaces below? 

 

 

 show interfaces diagnostics optics xe-1/0/18
Physical interface: xe-1/0/18
    Laser bias current                        :  41.878 mA
    Laser output power                        :  0.6590 mW / -1.81 dBm
    Module temperature                        :  47 degrees C / 117 degrees F
    Module voltage                            :  3.2800 V
    Receiver signal average optical power     :  0.0000 mW / - Inf dBm
    Laser bias current high alarm             :  Off
    Laser bias current low alarm              :  Off
    Laser bias current high warning           :  Off
    Laser bias current low warning            :  Off
    Laser output power high alarm             :  Off
    Laser output power low alarm              :  Off
    Laser output power high warning           :  Off
    Laser output power low warning            :  Off
    Module temperature high alarm             :  Off
    Module temperature low alarm              :  Off
    Module temperature high warning           :  Off
    Module temperature low warning            :  Off
    Module voltage high alarm                 :  Off
    Module voltage low alarm                  :  Off
    Module voltage high warning               :  Off
    Module voltage low warning                :  Off
    Laser rx power high alarm                 :  Off
    Laser rx power low alarm                  :  On
    Laser rx power high warning               :  Off
    Laser rx power low warning                :  On
    Laser bias current high alarm threshold   :  70.000 mA
    Laser bias current low alarm threshold    :  1.000 mA
    Laser bias current high warning threshold :  68.000 mA
    Laser bias current low warning threshold  :  2.000 mA
    Laser output power high alarm threshold   :  2.2380 mW / 3.50 dBm
    Laser output power low alarm threshold    :  0.0600 mW / -12.22 dBm
    Laser output power high warning threshold :  1.1220 mW / 0.50 dBm
    Laser output power low warning threshold  :  0.1510 mW / -8.21 dBm
    Module temperature high alarm threshold   :  75 degrees C / 167 degrees F
    Module temperature low alarm threshold    :  -5 degrees C / 23 degrees F
    Module temperature high warning threshold :  70 degrees C / 158 degrees F
    Module temperature low warning threshold  :  0 degrees C / 32 degrees F
    Module voltage high alarm threshold       :  3.630 V
    Module voltage low alarm threshold        :  2.970 V
    Module voltage high warning threshold     :  3.465 V
    Module voltage low warning threshold      :  3.135 V
    Laser rx power high alarm threshold       :  2.2387 mW / 3.50 dBm
    Laser rx power low alarm threshold        :  0.0145 mW / -18.39 dBm
    Laser rx power high warning threshold     :  1.1220 mW / 0.50 dBm
    Laser rx power low warning threshold      :  0.0363 mW / -14.40 dBm

> show interfaces diagnostics optics xe-0/0/10
Physical interface: xe-0/0/10
    Laser bias current                        :  42.444 mA
    Laser output power                        :  0.6320 mW / -1.99 dBm
    Module temperature                        :  49 degrees C / 121 degrees F
    Module voltage                            :  3.2600 V
    Receiver signal average optical power     :  0.3278 mW / -4.84 dBm
    Laser bias current high alarm             :  Off
    Laser bias current low alarm              :  Off
    Laser bias current high warning           :  Off
    Laser bias current low warning            :  Off
    Laser output power high alarm             :  Off
    Laser output power low alarm              :  Off
    Laser output power high warning           :  Off
    Laser output power low warning            :  Off
    Module temperature high alarm             :  Off
    Module temperature low alarm              :  Off
    Module temperature high warning           :  Off
    Module temperature low warning            :  Off
    Module voltage high alarm                 :  Off
    Module voltage low alarm                  :  Off
    Module voltage high warning               :  Off
    Module voltage low warning                :  Off
    Laser rx power high alarm                 :  Off
    Laser rx power low alarm                  :  Off
    Laser rx power high warning               :  Off
    Laser rx power low warning                :  Off
    Laser bias current high alarm threshold   :  85.000 mA
    Laser bias current low alarm threshold    :  15.000 mA
    Laser bias current high warning threshold :  80.000 mA
    Laser bias current low warning threshold  :  20.000 mA
    Laser output power high alarm threshold   :  1.5840 mW / 2.00 dBm
    Laser output power low alarm threshold    :  0.1580 mW / -8.01 dBm
    Laser output power high warning threshold :  1.2580 mW / 1.00 dBm
    Laser output power low warning threshold  :  0.1990 mW / -7.01 dBm
    Module temperature high alarm threshold   :  88 degrees C / 190 degrees F
    Module temperature low alarm threshold    :  -13 degrees C / 9 degrees F
    Module temperature high warning threshold :  85 degrees C / 185 degrees F
    Module temperature low warning threshold  :  -8 degrees C / 18 degrees F
    Module voltage high alarm threshold       :  3.700 V
    Module voltage low alarm threshold        :  2.900 V
    Module voltage high warning threshold     :  3.600 V
    Module voltage low warning threshold      :  3.000 V
    Laser rx power high alarm threshold       :  1.7783 mW / 2.50 dBm
    Laser rx power low alarm threshold        :  0.0100 mW / -20.00 dBm
    Laser rx power high warning threshold     :  1.5849 mW / 2.00 dBm
    Laser rx power low warning threshold      :  0.0158 mW / -18.01 dBm

> show interfaces terse xe-0/0/10
Interface               Admin Link Proto    Local                 Remote
xe-0/0/10               up    up
xe-0/0/10.0             up    up   eth-switch

> show interfaces terse xe-1/0/18
Interface               Admin Link Proto    Local                 Remote
xe-1/0/18                up    down
xe-1/0/18.0              up    down inet

 

 

2 REPLIES 2
Highlighted
Ethernet Switching

Betreff: optics

‎05-27-2020 02:46 AM

Hello Arix,

 

the attributes "Laser output power" and "Receiver signal average optical power" are the most important ones.

The first one shows you if the transceiver sends out a signal, the second one shows you if the transceiver receives a signal.

 

In this specific case, xe-0/0/10 sends out and receives a signal, but xe-1/0/18 just sends out a signal, it does not receive anything, as indicated with "- Inf dBm".

 

There are several possibilites for the root cause. One is a faulty fiber cable, but it could be one of the both transceivers as well.

My suggestion is to replace the cabling at first. If this does not help, replace one transceiver after another with a replacement transceiver. 

--------------------------------------------------

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Highlighted
Ethernet Switching

Re: optics

[ Edited ]
‎05-27-2020 02:46 AM

Hi Arix,

 

If you compare the diagnostic outputs, you can see the below in xe-1/0/18:

    Laser rx power low alarm                  :  On
    Laser rx power high warning               :  Off
    Laser rx power low warning                :  On

Which says there is a low rx (receive)  power which has triggered an alarm and already warning condition. This could be the reason. Also, if you see in the "show interfaces terse" output for xe-1/0/18, you can see that it is administratively UP. Which holds true as per the above warnings. The warnings indicate the issue is with the laser power being received and not the local optic. 

 

To resolve this, you might want to consider troubleshooting the peer end/transit devices. You may also consider a loopback test to isolate the issue.

 

Hope this helps  🙂

 

Please mark "Accepted Solution" so that it can help others.

Kudos are always appreciated!

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