[c-nsp] Optics warnings - SR /LH Modules SFP+

[Nick Cutting]

Good Morning FiberMasters,



I know very little about fibre and was hoping someone could shed some light upon the two conundrums below.



The first Issue I have is with SR modules



I have 2 4500-E's with Sup8's

There are connected in a 40 Gig port channel, using 10GBase-SR modules and 3 metre and 5 metre cables. They have wildly different power values, and Te5/1 filling up syslog with THRESHOLD error messages.  It is using the same Cable type (OM3 I think) as the other 3 links - does this mean the SFP is faulty?



*Jul 21 00:24:49.534 UTC: %SFF8472-5-THRESHOLD_VIOLATION: Te5/1: Rx power high warning; Operating value:  -0.7 dBm, Threshold value:  -1.0 dBm.

*Jul 21 00:34:49.633 UTC: %SFF8472-5-THRESHOLD_VIOLATION: Te5/1: Rx power high warning; Operating value:  -0.7 dBm, Threshold value:  -1.0 dBm.

*Jul 21 00:44:49.734 UTC: %SFF8472-5-THRESHOLD_VIOLATION: Te5/1: Rx power high warning; Operating value:  -0.8 dBm, Threshold value:  -1.0 dBm.



sh int transceiver

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)

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

Te5/1        26.2       3.29      -2.2      -0.7

Te5/2        29.5       3.28      -2.1      -2.1

Te6/1        27.6       3.28      -2.1      -2.9

Te6/2        27.8       3.28      -2.1      -2.2





# sh int Te5/1 capabilities | in Model

  Model:                 WS-X45-SUP8-E-Gbic

# sh int Te5/2 capabilities | in Model

  Model:                 WS-X45-SUP8-E-Gbic

# sh int Te6/1 capabilities | in Model

  Model:                 WS-X45-SUP8-E-Gbic

# sh int Te6/2 capabilities | in Model

  Model:                 WS-X45-SUP8-E-Gbic



The other side, looks normal - Shouldn't the TX match the RX on the other side? - Or is the discrepancy due to a faulty cable?



sh int transceiver

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)

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

Te5/1        28.7       3.27      -2.1      -2.1

Te5/2        27.8       3.28      -2.1      -2.8

Te6/1        26.3       3.28      -2.1      -2.3

Te6/2        27.0       3.28      -2.1      -2.0



The second issue is with a link to an upstream ISP that has contacted me regarding errors on their side that the RX is also too high on a 1000BaseLH module.  Are there minimum distances for these modules as they are expected for longer distances?  I am using the same cables on this link, it's about 3 metres into the ME3400 as in the SR modules.  Also - does anyone know why the sh int transceiver command is not available for this module?



What kind of cables would you typically use for each of these modules?  Is this a faulty module - or do I need use different cables i.e. different types of OM3. Can anyone point me towards a comprehensive Module -> cabling guide ?



Thank you,

Nick Cutting