Hi Drew, I have seen both N/A (none) and -40 dBm (lower limit) on optics.
It seems to depend on the optic--so maybe the codings are different. I wouldn't consider either behaviour "broken". When I see N/A or -40, I read those both as "no light received by the optic". Cheers, Jonathan On Tue, Jul 21, 2026 at 9:20 AM Drew Weaver via cisco-nsp < [email protected]> wrote: > Howdy, > > I noticed that one QSFP-40G-PLRL4 (that doesn't appear to be working) is > saying N/A for Rx Power: > > Lane Number:1 Network Lane > SFP Detail Diagnostics Information (internal calibration) > > ---------------------------------------------------------------------------- > Current Alarms Warnings > Measurement High Low High Low > > ---------------------------------------------------------------------------- > Temperature 39.68 C 80.00 C -10.00 C 75.00 C -5.00 > C > Voltage 3.27 V 3.70 V 2.90 V 3.59 V 3.00 > V > Current 34.63 mA 75.00 mA 10.00 mA 70.00 mA 15.24 > mA > Tx Power -1.61 dBm 4.49 dBm -8.72 dBm 3.99 dBm -8.21 > dBm > Rx Power N/A 4.50 dBm -12.50 dBm 4.00 dBm -11.49 > dBm > > I've never seen N/A normally without signal I see something like Rx Power > -40.00 dBm - > > Is this just perhaps a badly coded transceiver or a broken one? > > Thanks, > -Drew > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ > -- Jonathan _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
