cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
1581
Views
0
Helpful
2
Replies
Luciano Vigano'
Beginner

TX Power -40db

Ciao,

 

we are just facing a strange behavior on a FO SM link (span is about 2km).

The link connects one 4506 with X2-10GB-LR to a Nexus 3548 with a 10Gbase-LR: the link is up & running.

The strange behavior is the TX power registered by the X2:

KL-MENARA-CORE#sh int te1/4/1 trans det
ITU Channel not available (Wavelength not available),
Transceiver is internally calibrated.
mA: milliamperes, dBm: decibels (milliwatts), NA or N/A: not applicable.
++ : high alarm, +  : high warning, -  : low warning, -- : low alarm.
A2D readouts (if they differ), are reported in parentheses.
The threshold values are calibrated.

                              High Alarm  High Warn  Low Warn   Low Alarm
          Temperature         Threshold   Threshold  Threshold  Threshold
Port       (Celsius)          (Celsius)   (Celsius)  (Celsius)  (Celsius)
--------- ------------------  ----------  ---------  ---------  ---------
Te1/4/1      9.1                74.0        70.0         0.0       -4.0

                              High Alarm  High Warn  Low Warn   Low Alarm
           Voltage            Threshold   Threshold  Threshold  Threshold
Port       (Volts)            (Volts)     (Volts)    (Volts)    (Volts)
---------  ---------------    ----------  ---------  ---------  ---------
Te1/4/1    3.32                   N/A         N/A         N/A        N/A

           Optical            High Alarm  High Warn  Low Warn   Low Alarm
           Transmit Power     Threshold   Threshold  Threshold  Threshold
Port       (dBm)              (dBm)       (dBm)      (dBm)      (dBm)
---------  -----------------  ----------  ---------  ---------  ---------
Te1/4/1    -40.0                 4.4         0.4        -8.2      -12.2

           Optical            High Alarm  High Warn  Low Warn   Low Alarm
           Receive Power      Threshold   Threshold  Threshold  Threshold
Port       (dBm)              (dBm)       (dBm)      (dBm)      (dBm)
-------    -----------------  ----------  ---------  ---------  ---------
Te1/4/1     -7.0                 4.4         0.4       -14.4      -18.4

 

As you can see it registering a -40.0 TX .... on the other side:

 

KL-MENARA-L201# sh int Ethernet1/23 trans det
Ethernet1/23
    transceiver is present
    type is 10Gbase-LR
    name is OEM
    part number is SFP+-LR
    revision is
    serial number is FNS16480367
    nominal bitrate is 10300 MBit/sec
    Link length supported for 9/125um fiber is 10 km
    cisco id is --
    cisco extended id number is 4

           SFP Detail Diagnostics Information (internal calibration)
  ----------------------------------------------------------------------------
                Current              Alarms                  Warnings
                Measurement     High        Low         High          Low
  ----------------------------------------------------------------------------
  Temperature   32.51 C        80.00 C    -10.00 C     70.00 C        0.00 C
  Voltage        3.20 V         3.63 V      2.97 V      3.46 V        3.13 V
  Current       49.50 mA      110.00 mA     1.00 mA   100.00 mA       1.00 mA
  Tx Power       -0.41 dBm       2.49 dBm  -10.22 dBm    0.49 dBm     -8.21 dBm
  Rx Power       -7.67 dBm       2.49 dBm  -16.57 dBm    0.49 dBm    -14.43 dBm
  ----------------------------------------------------------------------------
  Note: ++  high-alarm; +  high-warning; --  low-alarm; -  low-warning


As you can see below the ports are connected together:

 

KL-MENARA-L201# sh udld ne
Port             Device Name    Device ID   Port ID         Neighbor State
--------------------------------------------------------------------------
Ethernet1/21     FOC1852R04H    1           Ethernet1/21    bidirectional
Ethernet1/22     FOC1852R04H    1           Ethernet1/22    bidirectional
Ethernet1/23     SPE184700LE    1           Te1/4/1         bidirectional

 

Any Idea ?

 

BR,

Luciano

2 REPLIES 2
kayukovvalera
Beginner

Try to change sfp, it looks like it damaged. If power of other sfp will goot, it mean that original is broken.

viyuan700
Contributor

Too much loss in 2Km of fiber. First check fiber if you have more than a pair in the same cable then try other fibers. If fiber is fine then check SFP.