WLC code 8.2 - AP Interference value in Main Dashboard differs from traditional view

[patrick.kofler]

Hi all,

I am currently checking out the new main dashboard in WLC code 8.2. I took one AP, which shows a very high interference percentage (>70%).

I compared it to the values of the values in the traditional view (Advanced -> Monitor -> 802.11b/g/n -> AP name -> Detail). When checking the interference Profile values of the 2.4GHz radio they don't add up (didn't check 5GHz). The channel is clean according to the traditional view - Interference Profile states Passed - and 73% in the main dashboard.

Here are the respective screenshots.

Traditional view

New view

Does anybody know, if I might be missing something. Is there is something else added to to this parameter in the new dashboard, which is not accounted for in the traditional view?

Best Regards,
Patrick

[George Stefanick]

Yea, that does look right. Im not sure what the answer to this one is. Im not on 8.2 yet. Let see if someone else answers. Did you open a TAC case?

[patrick.kofler]

Yep,

TAC case is open. I'll post the info, once I know more.

Regards,
Patrick

[patrick.kofler]

Totally forgot to update this.

The case is already closed and it turned out to be a bug with the traditional view. For anyone running into this issue, this is the bug ID:

CSCuy64601 - WLC GUI Wireless dashboard AP performance Interference data inconsistent

The way to look at those values should be done over the new dashboard view. A short description on reading the values according to TAC:

1. “Traffic” is the value as is sum of   rX + Tx  Utilization
2. “Channel utilization” is the same value as shown in Legacy “Load Statistics”.
3. “Interference” is the value “Channel Util” – “Traffic”.
4. “Air Quality” is from the Clean Air data for the AP.

Best Regards,
Patrick

[chakarav7]

Hi,

Can anyone confirm the below & will match this bug..?

running version : 8.2.151.0

interference : 72%

channel Utilization : 74%

  Radio Type..................................... RADIO_TYPE_80211b/g
  Sub-band Type.................................. All
  Noise Information
    Noise Profile................................ PASSED
    Channel 1....................................  -98 dBm
    Channel 2....................................  -99 dBm
    Channel 3....................................  -80 dBm
    Channel 4....................................  -93 dBm
    Channel 5....................................  -98 dBm
    Channel 6....................................  -95 dBm
    Channel 7....................................  -94 dBm
    Channel 8....................................  -88 dBm
    Channel 9....................................  -98 dBm
    Channel 10...................................  -95 dBm
    Channel 11...................................  -97 dBm
    Channel 12...................................  -97 dBm
    Channel 13...................................  -91 dBm

--More-- or (q)uitt 0..................  -73 dBm on   1  20MHz (172.16.0.201)  M3-AP-1

  Interference Information
    Interference Profile......................... PASSED
    Channel 1.................................... -128 dBm @  0 % busy
    Channel 2.................................... -128 dBm @  0 % busy
    Channel 3.................................... -128 dBm @  0 % busy
    Channel 4.................................... -128 dBm @  0 % busy
    Channel 5.................................... -128 dBm @  0 % busy
    Channel 6.................................... -128 dBm @  0 % busy
    Channel 7.................................... -128 dBm @  0 % busy
    Channel 8.................................... -128 dBm @  0 % busy
    Channel 9.................................... -128 dBm @  0 % busy
    Channel 10................................... -128 dBm @  0 % busy
    Channel 11................................... -128 dBm @  0 % busy
    Channel 12................................... -128 dBm @  0 % busy
    Channel 13................................... -128 dBm @  0 % busy
    Rogue Histogram (20)
    .............................................
    Channel 1....................................  1
    Channel 2....................................  0
    Channel 3....................................  0
    Channel 4....................................  0
    Channel 5....................................  0
    Channel 6....................................  9

--More-- or (q)uit
    Channel 7....................................  0
    Channel 8....................................  0
    Channel 9....................................  0
    Channel 10...................................  0
    Channel 11...................................  0
    Channel 12...................................  0
    Channel 13...................................  0
  Load Information
    Load Profile................................. PASSED
    Receive Utilization.......................... 0 %
    Transmit Utilization......................... 2 %
    Channel Utilization.......................... 78 %
    Attached Clients............................. 0 clients
  Coverage Information
    Coverage Profile............................. PASSED
    Failed Clients............................... 0 clients
  Client Signal Strengths
    RSSI -100 dbm................................ 0 clients
    RSSI  -92 dbm................................ 0 clients
    RSSI  -84 dbm................................ 0 clients
    RSSI  -76 dbm................................ 0 clients
    RSSI  -68 dbm................................ 1 clients
    RSSI  -60 dbm................................ 0 clients

--More-- or (q)uit
    RSSI  -52 dbm................................ 0 clients
  Client Signal To Noise Ratios
    SNR    0 dB.................................. 0 clients
    SNR    5 dB.................................. 0 clients
    SNR   10 dB.................................. 0 clients
    SNR   15 dB.................................. 1 clients
    SNR   20 dB.................................. 0 clients
    SNR   25 dB.................................. 0 clients
    SNR   30 dB.................................. 0 clients
    SNR   35 dB.................................. 0 clients
    SNR   40 dB.................................. 0 clients
    SNR   45 dB.................................. 0 clients

please find the attached img.

Thanks,

KV

[patoberli]

I haven't that in my installation, but I see that you have at least one 802.11b rate active. If you don't anymore have any 802.11b clients, disable all 802.11b rates for much improved performance. See more information here:

http://www.cisco.com/c/en/us/products/collateral/wireless/aironet-1250-series/design_guide_c07-693245.pdf - Page 36+

And here more: https://blogs.cisco.com/wireless/bring-out-yer-dead-5-steps-to-eliminate-802-11b-from-your-networks

[Freerk Terpstra]

I think that the old interference information is wrong or might have been based on non 802.11 signals and that the 8.2 actually does take this information into account. If this is the case this does make sense to me: channel utilization displays the actually capacity of the channel but if 70% is from foreign networks there is not much you can do about it.

I need to check what 8.0 controllers show, but 0% interference in 802.11b/g/n seems wrong unless you are in the middle of nowhere... :-)

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