Wireless Access

Hello everyone,

I have very little technical expertise so bear with me here. I have looked through the knowledge base in regards to pulling RSSI information off of Aruba125AP routers but was not able to find anything. I'm trying to find a way to access RSSI information from the aruba125AP, and then export this information into mySQL with a timestamp.

Would anyone be able tell me how I would go about doing this? I'm not sure if you need more information about the network to answer the question, but if that is the case I can get the info you need. If I can find out how to access the RSSI info for each access point I can probably figure out the rest, but any suggestions or tips would be very much aprecciated.

Additionally, I want to make sure that getting this info from the routers isn't going to perfect the performance of the network! Do you think this would be a problem?

This sort of fell onto my lap, and I'm on a tight schedule to figure this out. Please help!

Henry S.

You can use this CLI command to get the SNR value from an associated client: 

show ap association client-mac <MAC>

You can also pull this information from SNMP if needed, I'm not sure what is practical for you?

Hi Arjan,

Thank you for the prompt response, very helpful. To be honest I'm not sure if it would make more sense to use tha CLI command or to do something with SNMP. Do you know the CLI command for RSSI values? I know that there is an arbitrary RSSI measurement and one in dBm (I don't know if Aruba uses both). We are more interested in RSSI than SNR.

My biggest concern is that asking for this information for a large number of AP could somehow slow the network down so I would prefer to use whichever method minimizes that risk. It's also important that I am able to timestamp RSSI info from different AP--everything needs to be synchronized (not 100% synchronization, but as close as possible).

Thanks again, you've already been helpful.

-H

The output of "show ap association client-mac" will actually show you the SNR value (in dB) and channel noise floor (in dBm). If you subtract the noise floor minus the SNR value you will get the signal in dBm.

@networknewb , 

RSSI Is Received Signal Strength. This means it is only the value between two radios. It is a value of how well a radio is picking up another radio. An Access point does not have a single RSSI value. An access point has an rssi each and every 802.11 radio it can hear. Avalue for each client connected. The access point can also have RSSI value for neighboring Access points. How load this access points hears another. 

Further, this would only give you a measurement for uplink traffic. Unless you went to each client and pulled the RSSI value for the AP.

And even Furthermore :-) RSSI is not a concrete value. Many many many chipset manufactures calculate RSSI and SNR differently.

You could possible get a report from Airwave or controller comand of APs that have clients with a low RSSI value. 

Thank you Sean.

When I say we want to pick up RSSI values, I meant exactly what you described. We are interested in each RSSI between each AP. We understand that 802.11 does not clearly define RSSI values and that they are to some degree arbitrary--this is okay.

We are most interest in figuring out how to generate the AIRWAVE report. The other option, as you mentioned, is to use some sort of CLI command to pull this information. I am not experienced enought to know how to do this and am trying to figure out step-by-step instructions.

I am requesting this information from a network manager that is unwilling to spend significant time helping to figure this out. He is not familiar with accessing RSSI information. However, if I can give him step-by-step instructions he will not have any excuses left. This is what I am after. Thanks for your response, I appreciate it.

Henry S.