topic Re: RF spectrum help in Wireless

RF spectrum help

ZedKay — Fri, 18 Nov 2022 05:54:53 GMT

I'm seeking a bit of help on understanding our RF spectrum graph.

We had a report of some client issues - packets being dropped on ping to 8.8.8.8.

The AP is operating on ch 161, it is a MR57

Taking a look at the RF spectrum graph ch 161 did not look like it was operating normally.

I'm trying to determine if it is a source of RF interference, or the AP is misbehaving/faulty.

I've looked at other causes of the potential packet loss - but everything else looked normal.

Any help would be appreciated.

Re: RF spectrum help

CMR — Fri, 18 Nov 2022 11:05:32 GMT

Here you can see an AP on channel 40 that is slightly suffering, but in realist is working fine, what does the table below show for your one?

In terms of diagnostics there is a lot of infrastructure between your client and Google's DNS servers, so I would ping the local gateway for a better test of the AP and local switch / router only. If that shows loss and pinging it from a wired device does not then the wireless is where to investigate.

Re: RF spectrum help

ZedKay — Fri, 18 Nov 2022 11:25:54 GMT

Hi cmr,

I'll check out pinging the gateway, and from a wired device - good idea.

i've attached the table as well.

Re: RF spectrum help

CMR — Fri, 18 Nov 2022 11:32:03 GMT

The utilisation of 161 is 0% so that shouldn't be the problem, though I did check a 9166 and the graph is all over the place. Newer models often take a while for this part to be right...

Re: RF spectrum help

jgbright — Fri, 18 Nov 2022 21:02:03 GMT

I have seen multiple instances where ping is not 100% reliable to the Google DNS servers, even with a wired connection and a fiber internet connection. I would suggest you also try to ping against the Cisco Umbrella servers at 208.67.222.222 and 208.67.220.220 and see how they respond. And if you really want to understand what is going on with an internet connection, a Cisco Thousand Eyes subscription will show the performance of every hop between your connection to the internet and any other device connected to the internet.