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rilliam
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ghost snooper records / 20dB signal loss

Thu Apr 01, 2021 10:08 pm

I have configured a 5gig wireless bridge between a wAP G-5HacT2HnD and a 962UiGS-5HacT2HnT. When I initially set it up the signal to noise reported from the wap was 51dB. Two days later the signal to noise is 29dB. I have disabled the other radios and the noise floor hasn't changed. Noise floor reported at the wap is -99dB. The signal to noise at the 962 hasn't changed much, its dropped a couple dB from 46 to 44.

The distance of the bridge is about 20 feet through a couple walls of drywall and 2x4 construction.

Previously I had the bandwidth of the bridge set at 20/40/80 and this was not working well at all, so I changed it to 20 and this seemed to make it work.

I performed a wireless snoop and I am confused by the number of records that have no data and report a large number of stations. (attached).

Turning on nv2 has seemed to dramatically help but I am still concerned about the drop in signal.

Why would there be such a decrease in signal level overnight like this?
What are these records in the snooper with data and what is the relevance of the station count associated with them, if any?
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Last edited by rilliam on Wed Apr 07, 2021 8:53 pm, edited 1 time in total.
 
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bpwl
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Re: 20dB drop overnight

Fri Apr 02, 2021 1:41 am

I performed a wireless snoop and I am confused by the number of records that have no data and report a large number of stations. (attached).

In Snooper, you have frequencies (channels), networks and stations. Frequencies do not report MAC addresses, they are in the network and station lines.
Either use the filter (upper top right, then you will also understand the different symbols), or sort them by channel. (Frequency lines are a consolidation of networks and stations)
 
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rilliam
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Re: 20dB drop overnight

Wed Apr 07, 2021 8:22 pm

@bpwl - I appreciate the response, but that doesn't answer my question, I did have a typo so maybe that makes a difference:

What are these records in the snooper without data and what is the relevance of the station count associated with them, if any?

You simply say, "oh those are just frequencies". But what does that mean? Is it just random noise or are there data packets on it? If there are data packets on it what are they?

Since my original post, those records in the snooper that are missing data, have dropped out and now I am getting 53dB and 43dB signal strength at the router and wap respectively. This leads me to believe that these records are the cause of the problem I am having whereby I am getting a 20dB drop in signal strength. So it would be really nice to know more about what those records are representing in the snooper output.

Thanks.
 
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bpwl
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Re: ghost snooper records / 20dB signal loss

Wed Apr 07, 2021 9:27 pm

What do you mean without data?

- sometimes SSID is missing (hidden SSID network, not well decoded SSID, non-802.11 based device (nv2 will be recognized by snooper as it is also MT) but other protocols will not be decoded.
- sometimes power reading is missing or is also missing
- signal that is not current will be grayed out
- freq lines show # of networks and stations seen on that freq. (channel information may leak to adjacent channels, so you may see in 2417 a 2412 station)
- sometimes information is seen double (small differences for snooper) but with the same MAC address
- the microwave oven has no mac address, but bluetooth will probably appear with no other information but MAC address (I never managed to identify a bluetooth so far.)
.
Klembord-2.jpg
If you set "receive errors" enabled in "settings" you may see more lines, but with some errors in the decoded information (typical are weird SSID names)
Klembord-3.jpg
And DO click on "channel", to sort the lines per freq. There you will see that freq line is the consolidation of the network and station lines (sum may not be correct as thing come and go rapidly).
Or do use the upper right filter to show networks or stations only.
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bpwl
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Re: ghost snooper records / 20dB signal loss

Wed Apr 07, 2021 9:52 pm

Simple example: Omnitik looking at ISP modem in other room. One AP, one station being the AP itself, 3 xxxx from neighbors

All view (remark: frequency= AP= stations in traffic)
Freq sees 1 network and 4 stations in the same freq
network sees 1 station in that network
(the 3 neighbors are silent now)
Klembord-2.jpg
.
.
Selective view (screenshot takes some time, so data is not consistent)

Klembord-3.jpg
Klembord-4.jpg
Klembord-7.jpg
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