Monitoring Rx/Tx Power, Bias Current and Temperature on the following devices: WSC6503, 7206VXR, cat6509 using CISCO-ENTITY-SENSOR-MIB

[charalambides.savvas]

Hello,

I am trying to monitor the following parameters via SNMP on some Cisco switches and routers regarding individual transceivers that are present on these devices:

• RxPower
• TxPower
• Bias Current
• Temperature

I have accomplished this for an ASR Router using the ENTITY-MIB and CISCO-ENTITY-SENSOR-MIB. However, following the same approach for the following  devices I could not get the values I require as was the case for the ASR Router:

• WSC6503
• 7206VXR
• cat6509

Namely, I get results for a variety of sensors but not values for sensors regarding specific transceivers. For example, on the ASR router I get values for sensors like: subslot 0/0 transceiver 0 Temperature Sensor, subslot 0/0 transceiver 0 Bias Current Sensor, subslot 0/0 transceiver 0 Tx Power Sensor and subslot 0/0 transceiver 0 Rx Power Sensor.

My question is  whether  the three devices I mentioned above support the CISCO-ENTITY-SENSOR-MIB and can I monitor the parameters I want for specific transceivers on these devices as I am currently doing for the ASR Router?

[Vinod Arya]

SNMP MIB support is as per the hardware and software. IOS device has CISCO-ENTITY-SENSOR-MIB as a very common supported device.

You can check the supported list here:

http://tools.cisco.com/ITDIT/MIBS/MainServlet

Usually you get the CLI's show output command like this :

            Temperature  Voltage  Current   Tx Power  Rx Power

Port        (Celsius)       (Volts)     (mA)       (dBm)      (dBm)

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

Gi1/25        41.5           3.32      21.1           2.6         -3.4

Out of this, if you want to get the Tx/Rx power details via SNMP, check the following details.

n CLI as we see a collaborated output where it shows different values together. All sensors above in bold-yellow are hardware sensors and using cli command for hardware-entity index mapping we found the following details:

N1GGNACG17xxxACR002#sh snmp mib entity indexmapping | include Gi1/25

1047                          Transceiver Gi1/25

1048                      Gi1/25 Module Temperature Sensor

1049                      Gi1/25 Supply Voltage Sensor

1052                      Gi1/25 Receive Power Sensor

1051                      Gi1/25 Transmit Power Sensor

So the Hardware entity to SNMP Index mapping is as follows :

SNMP Index       Hardware Entity             

1047 --                  Transceiver Gi1/25

1048 --                  Gi1/25 Module Temperature Sensor 

1049 --                 Gi1/25 Supply Voltage Sensor     

1050 --                  Gi1/25 Bias Current Sensor

1051 --                  Gi1/25 Transmit Power Sensor

1052 --                  Gi1/25 Receive Power Sensor

After we get the required index number about the sensors we have to poll the device for entSensorValue which can bring the similar value to Show command (show interface <int_id> transceiver):

[root@mrtgnew ~]# snmpwalk -v 2c -c cisco1 192.168.8.199 enterprises.9.9.91.1.1.1.1.4.1048

SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1048 = INTEGER: 417

[root@mrtgnew ~]# snmpwalk -v 2c -c cisco1 192.168.8.199 enterprises.9.9.91.1.1.1.1.4.1049

SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1049 = INTEGER: 33

[root@mrtgnew ~]# snmpwalk -v 2c -c cisco1 192.168.8.199 enterprises.9.9.91.1.1.1.1.4.1050

SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1050 = INTEGER: 211

[root@mrtgnew ~]# snmpwalk -v 2c -c cisco1 192.168.8.199 enterprises.9.9.91.1.1.1.1.4.1051

SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1051 = INTEGER: 26

[root@mrtgnew ~]# snmpwalk -v 2c -c cisco1 192.168.8.199 enterprises.9.9.91.1.1.1.1.4.1052

SNMPv2-SMI::enterprises.9.9.91.1.1.1.1.4.1052 = INTEGER: -34

Matching the output with CLI:

                                         Optical   Optical

            Temperature  Voltage  Current   Tx Power  Rx Power

Port        (Celsius)       (Volts)     (mA)       (dBm)      (dBm)

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

Gi1/25        41.5           3.32      21.1           2.6         -3.4  

In the SNMP output there is no decimal value which is default 1 for this device. Means the decimal would be before last integer. To check where exactly the decimal should be applied the device or entity can be polled for entSensorPrecision. Its output tells the decimal value location, in this device the output by polling entSensorPrecision should come to 1.

-Thanks

Vinod

**Encourage Contributors. RATE Them.**

[charalambides.savvas]

Dear Vinod Arya,

Thank you for your response. The methodology you propose is the one I am currently following for the ASR Router and it works.

However, the problem I am having is that for the other devices I mentioned in my first post (WSC6503, 7206VXR, cat6509) I cannot get the values I require (RxPower, TxPower, Bias Current, Temperature) for specific transceivers.

Namely, when I do an SNMP walk on 1.3.6.1.2.1.47.1.1.1.1.2 (entPhysicalDescr), I do not get descriptions for specific sensors that refer to transceivers' port/slot as is the case with the ASR Router where I do get for example, as mentioned in my original post, the following:

• subslot 0/0 transceiver 0 Temperature Sensor
• subslot 0/0 transceiver 0 Bias Current Sensor
• subslot 0/0 transceiver 0 Tx Power Sensor
• subslot 0/0 transceiver 0 Rx Power Sensor

Based on the description shown above I get the indexes and then do SNMP GETs using the appropriate OID from the CISCO-ENTITY-SENSOR MIB.

Is it possible that the aforementioned devices do not have sensors for individual transceivers? Is there another way to monitor the parameters I require via SNMP other than using the CISCO-ENTITY-SENSOR MIB?

[Vinod Arya]

Do you see the desired output via CLI for these transceivers? It is important, as SNMP will pick the information from there.

-Thanks

Vinod