SNMP Polling of optical budget (dbm)

[Mickael Marchand]

Hi,

I can't seem to find an OID to monitor transceiver optics RX/TX as "dbm" on IOS-XR like we can do on catalyst/IOS devices for example

ENTITY-SENSOR-MIB only seems to report celsius/amperes/watts/voltsDC sensors ?

thanks

Mik

[xthuijs]

Hi Mik,

yup that can be done!

19: entPhysicalEntry.2.1189911 (EntPhysicalEntry) Transceiver Rx Power Sensor [54.72.61.6E.73.63.65.69.76.65.72.20.52.78.20.50.6F.77.65.72.20.53.65.6E.73.6F.72 (hex) Size = 27]
22: entPhysicalEntry.2.1894502 (EntPhysicalEntry) Transceiver Tx Power Sensor [54.72.61.6E.73.63.65.69.76.65.72.20.54.78.20.50.6F.77.65.72.20.53.65.6E.73.6F.72 (hex) Size = 27]

It is part of the entity-mib/entity-sensor mib,

but you need to enable the sysowner keyword on the community string definition.

cheers!

xander

[Mickael Marchand]

thanks Xander,

I will try to get that working in Librenms ;)

cheers,

Mik

[Mickael Marchand]

hmm still fighting with it :

snmpwalk -v2c -c xxxxx -m ENTITY-SENSOR-MIB -M . <some ASR9922> 1.3.6.1.2.1.47.1.1.1.1 | grep 2630860
ENTITY-MIB::entPhysicalDescr.2630860 = STRING: Transceiver Rx Power Sensor
ENTITY-MIB::entPhysicalVendorType.2630860 = OID: SNMPv2-SMI::enterprises.9.12.3.1.8.46
ENTITY-MIB::entPhysicalContainedIn.2630860 = INTEGER: 6656371
ENTITY-MIB::entPhysicalClass.2630860 = INTEGER: sensor(8)
ENTITY-MIB::entPhysicalParentRelPos.2630860 = INTEGER: 2
ENTITY-MIB::entPhysicalName.2630860 = STRING: power Rx 0/10/CPU0/4
ENTITY-MIB::entPhysicalHardwareRev.2630860 = STRING: 
ENTITY-MIB::entPhysicalFirmwareRev.2630860 = STRING: 
ENTITY-MIB::entPhysicalSoftwareRev.2630860 = STRING: 
ENTITY-MIB::entPhysicalSerialNum.2630860 = STRING: 
ENTITY-MIB::entPhysicalMfgName.2630860 = STRING: 
ENTITY-MIB::entPhysicalModelName.2630860 = STRING: 
ENTITY-MIB::entPhysicalAlias.2630860 = STRING: 
ENTITY-MIB::entPhysicalAssetID.2630860 = STRING: 
ENTITY-MIB::entPhysicalIsFRU.2630860 = INTEGER: false(2)

I do have the SystemOwner param on the snmp-server community line (XR 5.3.1)

did I miss something ?

thanks

Mik

[xthuijs]

few more things:

is hte mgbl pie loaded and operational? is the optic supporting DOM?

here is a sample output of it working:

:~ xthuijs$ snmpwalk -v2c -c public 10.86.188.99 1.3.6.1.2.1.47.1.1.1.1.7  | grep 1189911
SNMPv2-SMI::mib-2.47.1.1.1.1.7.1189911 = STRING: "power Rx 0/0/0/9"

:~ xthuijs$ snmpwalk -v2c -c public 10.86.188.99 1.3.6.1.4.1.9.9.91.1.1.1.1.4  | grep 1189911
SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1189911 = INTEGER: 213

RP/0/RSP0/CPU0:A9K-BNG#show controller gig 0/0/0/9 phy | i Power
Mon Aug 10 15:34:34.736 EDT
.....
        Tx Power:  0.17870 mW (-7.47875 dBm)
        Rx Power:  0.21390 mW (-6.69789 dBm)

xander

[Mickael Marchand]

thanks Xander,

all was fine, just did not know the OID to poll :)

so I got it this time :

SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.2630860 = INTEGER: 425

​which correctly match :

RP/0/RP0/CPU0:xxxx#show controllers te0/10/0/4 phy | i Power

        Tx Power:  0.70110 mW (-1.54220 dBm)
        Rx Power:  0.42580 mW (-3.70794 dBm)

thanks again

cheers

Mik

[Mickael Marchand]

but that's not a dbm value ! :P

is there a formula to convert to dbm ? (from what I read it was not that simple ?)

Mik

[xthuijs · Accepted solution]

oh ha yeah that is very simple: it is the 10*log(mW).

milli watts go into dB via a 10* the logarithm of (mw).

xander

[Mickael Marchand]

Ok then I have everything I need :)

cheers

Mik