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Feature Request: SFP Optical Diagnostics ("sh int transceiver" for those familiar)

Getting noticed

Feature Request: SFP Optical Diagnostics ("sh int transceiver" for those familiar)

Hey Meraki friends, 

 

May I humbly suggest (also done via make-a-wish) support for SFP optical diagnostics? I know the MS have amazing copper cable diagnostics that is immensely helpful, and if you were able to add optical diagnostics, it would complement those perfectly. 

For a long time, classic Cisco IOS operators have had the command 'show interface transceiver' to retrieve data from SFPs with DOM monitoring - not all SFPs do, in which case the command returns a blank output. But if the SFP is capable of diagnostic optical monitoring, you get a result like this: 

 

#sh int trans

If device is externally calibrated, only calibrated values are printed.

++ : high alarm, +  : high warning, -  : low warning, -- : low alarm.

NA or N/A: not applicable, Tx: transmit, Rx: receive.

mA: milliamperes, dBm: decibels (milliwatts).

 

                                 Optical   Optical

           Temperature  Voltage  Tx Power  Rx Power

Port       (Celsius)    (Volts)  (dBm)     (dBm)

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

Te1/1        30.2       3.32      -0.4      -2.8   

Te1/2        33.3       3.28      -1.6      -7.6   

Te1/3        25.3       3.16      -3.1      -3.6   

Te1/4        33.9       3.26      -1.8      -2.7   

Te1/7        30.0       3.23      -2.0      -5.2   

Te1/8        26.7       3.30      -0.6      -2.7   

 

 

Of particular use to me is TX and RX power, because one can then check for high optical loss which is frequently a precursor to the problem. 

As we know, Meraki always makes things easier for the user - so I would recommend a more friendly output, with "SFP does not support diagnostics" if they are not DOM-capable, and a nice table to go with the above output, and the values to be colored green for a good range, yellow for a marginal link (within 3dB of the receive power floor) and red if it is even lower than that (or higher - in case of a mismatched over-powered SFP). Currently, I do this by eye, cross-referencing the SFP datasheets to determine their minimum RX power levels to see if my results fall into an acceptable range.


PS: I've been doing a little bit of reading and apparently the DOM/DDM capabilities are standardized according to the SFP MSAs - so it's a well known mechanism. That should make it easier to figure out how to extract the data 🙂

2 REPLIES 2
Kind of a big deal

Re: Feature Request: SFP Optical Diagnostics ("sh int transceiver" for those familiar)

Yup!  I would love to have this too. I recently brought up a link over some really old OM2 fibre running ~700m using LX optics and mode conditioning patch cables and it would be helpful to know these details to see how strong the link actually is.  It is working, and operating at 1Gbps without errors... But I can't say how much room to spare we have levels wise.

Getting noticed

Re: Feature Request: SFP Optical Diagnostics ("sh int transceiver" for those familiar)

Well said - the only way to test at this point is to break the link and stick a fiber power meter on it, but of course, that's easier said than done, taking down a production link!

Inline power monitoring using SFP diagnostics would give us the ability to keep tabs on a link in a non-service-impacting manner.
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