having problem with cisco cwdm sfp

[Tony Cheng]

i'm testing the cisco CWDM between 2 switches, the issue is if i fully insert the LC connector on both end of the cwdm sfp then it won't work, but if i have one side fully inserted the LC typed fiber to the cwdm sfp, while leaving the the other end not fully inserted into the cwdm sfp then the interface will come up, why is that ?

[Tony Cheng]

below is a good case, if i left one end of the fiber LC connector losely inserted into the CWDM SFP, when the interface are up/up on both ends of the switches over CWDM SFP:

Test-SW01#

Test-SW01#sh int trans module 1

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)

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

Gi1/1/1      39.2       3.29       2.8      -8.0

Gi1/1/4      39.3       3.30       2.2      -9.0

Test-SW01#

below is bad case, when interface are down/'down, when i inserted both ends fully into the cwdm sfp:

[Tony Cheng]

below is bad case, that interface won't come up.

Test-SW01#sh int trans module 1

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)

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

Gi1/1/1      38.2       3.55 +     8.1 +   -40.0

Gi1/1/4      39.3       3.30       2.1      -9.1

quesiton is , is there any parameter i can configure on the switch to make the RX power from -40 to -8 ?

[Joseph W. Doherty]

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Posting

You might want to move this question to the Optical Networking forum.  (My guess would be you might need an attenuator.)