RSSI, channel utilization, clients counts on APs

Hello Guy,
I have around 100 APs
some showing 100% channel utilization with only 2 or 3 Clients connected to it. why ?
Some APs showing 38 clients connected but channel utilization is 24 %. why ?
Some APs shows 0 value.
Can any one clerify RSSI, channel utilization, clients counts on APs
thanks

Oh that .. If you look at these aps they dont have clients. That 0 shows the worse clients that the aps hears. No clients .. means no clients to have a signal .. so its zero ..
Make sense?
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

Similar Messages

Channel utilization - show ap auto-rf 802.11b

Question on the command "show ap auto-rf 802.11b <ap_name>". What is the period of time that is measured for:
    Channel Utilization.......................... 64 %
I am seeing high channel util. on certain AP's, but standing directly below the AP w/ spectrum analyzer, I see much lower util.%:
Basically, wondering if the measurement is from the exact time I launch the command, or if it's over say a 10 sec. period?
WLCCA shows highest Rx neighbor @ -71
complete output of the command:
(WiSM-slot8-1) >show ap auto-rf 802.11b ap-bhs-400-2
Number Of Slots.................................. 2
AP Name.......................................... ap-bhs-400-2
MAC Address...................................... 50:57:a8:d6:7d:6d
Slot ID........................................ 0
Radio Type..................................... RADIO_TYPE_80211b/g
Sub-band Type.................................. All
Noise Information
    Noise Profile................................ PASSED
    Channel 1.................................... -88 dBm
    Channel 2.................................... -89 dBm
    Channel 3.................................... -91 dBm
    Channel 4.................................... -94 dBm
    Channel 5.................................... -93 dBm
    Channel 6.................................... -93 dBm
    Channel 7.................................... -90 dBm
    Channel 8.................................... -87 dBm
    Channel 9.................................... -94 dBm
    Channel 10................................... -92 dBm
    Channel 11................................... -92 dBm
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
Load Information
    Load Profile................................. PASSED
    Receive Utilization.......................... 0 %
    Transmit Utilization......................... 1 %
    Channel Utilization.......................... 65 %
    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................................ 0 clients
    RSSI -60 dbm................................ 0 clients
    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.................................. 0 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
Nearby APs
    AP 00:0f:90:5e:2a:d0 slot 0.................. -73 dBm on 11 (10.252.1.2)
    AP 00:13:5f:56:e0:90 slot 0.................. -88 dBm on 11 (10.252.1.4)
    AP 00:13:5f:57:00:70 slot 0.................. -79 dBm on   1 (10.252.1.4)
    AP 00:16:9c:91:64:e0 slot 0.................. -43 dBm on 11 (10.252.1.2)
    AP 00:17:0f:db:2e:70 slot 0.................. -87 dBm on   1 (10.252.1.2)
    AP 00:17:df:35:43:90 slot 0.................. -90 dBm on   1 (10.252.1.10)
    AP 00:21:d8:d5:a2:40 slot 0.................. -91 dBm on   1 (10.252.1.12)
    AP 00:21:d8:d5:a8:90 slot 0.................. -91 dBm on   1 (10.252.1.12)
    AP 00:21:d8:d5:a8:c0 slot 0.................. -91 dBm on 11 (10.252.1.12)
    AP 00:21:d8:d5:ac:80 slot 0.................. -92 dBm on   1 (10.252.1.12)
    AP a4:56:30:5d:b0:a0 slot 0.................. -89 dBm on 11 (10.252.1.12)
    AP b4:e9:b0:b3:c8:70 slot 0.................. -91 dBm on 11 (10.252.1.18)
Radar Information
Channel Assignment Information
    Current Channel Average Energy............... -76 dBm
    Previous Channel Average Energy.............. -57 dBm
    Channel Change Count......................... 3
    Last Channel Change Time..................... Wed Jul 17 22:27:37 2013
    Recommended Best Channel..................... 1
RF Parameter Recommendations
    Power Level.................................. 1
    RTS/CTS Threshold............................ 2347
    Fragmentation Threshold...................... 2346
    Antenna Pattern.............................. 0
Persistent Interference Devices
Class Type                 Channel DC (%%) RSSI (dBm) Last Update Time
All third party trademarks are the property of their respective owners.
These are lined down a hallway (about 50' from ea. other). Looks to me like they are set for too high Tx and crowding chan. 1. I'll figure out the reason for that.
show advanced 802.11b txpower:
ap-bhs-400-1                     *1         *1/7 (22 dBm) [22/19/16/13/10/7/4/4]
ap-bhs-400-2                     *1         *1/7 (22 dBm) [22/19/16/13/10/7/4/4]
ap-bhs-400-3                     *11        *1/8 (23 dBm) [23/20/17/14/11/8/5/2]
ap-bhs-400-4                     *1         *1/7 (22 dBm) [22/19/16/13/10/7/4/4]
ap-bhs-400-5                     *11        *7/8 ( 5 dBm) [23/20/17/14/11/8/5/2]
ap-bhs-400-6                     *1         *1/7 (22 dBm) [22/19/16/13/10/7/4/4]
ap-bhs-451-1                     *6         *7/8 ( 5 dBm) [23/20/17/14/11/8/5/2]

Cool thx. Guessing "Load Interval". Looks like 60 seconds is the answer. Including output here for others...
show advanced 802.11b monitor
Default 802.11b AP monitoring
802.11b Monitor Mode........................... enable
802.11b Monitor Channels....................... Country channels
802.11b RRM Neighbor Discovery Type............ Transparent
802.11b AP Coverage Interval................... 180 seconds
802.11b AP Load Interval....................... 60 seconds
802.11b AP Noise Interval...................... 180 seconds
802.11b AP Signal Strength Interval............ 60 seconds
802.11b AP Neighbor Report Interval............ 180 seconds
802.11b AP Interference Report Interval........ 120 seconds

Please help me to understand what is the meaning of Acess point Channel utilization?

       please help me to understand what is the meaning of Acess point Channel utilization? If i want to mange the capacity of my Office Wi-Fi network what are the factor i need to monitor.

Hi Ankit,
Channel Utilization
The 802.11, 802.11b, and 802.11g standards use the same 2.4 GHz band. All must interoperate with each other, which introduces additional overhead reducing channel throughput. Many sites already have products using the Wi-Fi 2.4 GHz band. Additionally, there are many other products that use the same 2.4 GHz frequencies as used by Wi-Fi. Other products include Bluetooth, cordless phones, video game controllers, surveillance cameras, and microwave ovens.
Before the installation of the Cisco Unified Wireless Network, a site can be tested for channel interference and utilization with tools from AirMagnet, Wild Packets, Cognio, and others. The Wireless Control System (WCS) AP On-Demand Statistics Display report provides a spectrum review of the following:
•Noise by channel
•Interference by channel
•Client count versus RSSI
•Client count versus SNR
•Channel radar detection versus time
You can further refer the following links,
https://supportforums.cisco.com/thread/2212228
https://supportforums.cisco.com/thread/334981
For design guide following link might help,
http://www.cisco.com/en/US/docs/solutions/Enterprise/Education/SchoolsSRA_DG/SchoolsSRA_chap5.html

Prime 2.1 - Client count report based on ssid

Dear All,
Is it possible to extract the reports of client count per ap based on ssid..?
Like, AP Name (eg., 2ndFloorAP) --> SSID (Test)--> Client count for past 1day, 1 week, 1 month etc.
As of now i could see overall client count of an ap from prime not based on SSID (under device work center --> unified ap --> client over time --> client count on ap / client traffic on ap)

Hi Prasan,
Revisiting this issue, if you have your APs assigned to specific campus/building for your company, you can drill down to the specific AP and SSID that you want for that client count. The options that I used to run a report for one AP for one location that we have is as follows:
report title: <enter applicable name for report>
report by: AP by floor area
report criteria: choose edit and search for the location/building/campus and then the specific AP that you want from those fields. Then choose select.
Once back at the report screen you can set the next options:
connection protocol: select from drop down what you want if it is all clients, all wireless, etc.
The next drop down should allow you to select the specific SSID to what you want based upon the individual AP. Followed by the report time afterward. This report will output as a line graph showing the total number of clients based upon your search criteria and time frame. If you want to research client counts and see their mac address and IP ranges then you are limited to only seeing the current associated clients from the operation > work center flow while viewing the specific AP. Hope that helps.
Regards,
Brandon

Cisco Prime NCS - Alarms for Channel Utilization

Hello,
I have Prime NCS 1.3 with several WLCs (5508, 2504, etc.) configured.
I would like to receive an e-mail alert when an AP reached high channel utlization. Is this possible with Prime NCS? In checking, I don't see any way to create customized events or alarms. I have monitoring templates, but they do not directly apply to wireless statistics.
David

Thanks for your response. Maybe there's another approach what I am trying to do. I need to know when an AP is providing poor client performance due to events like high channel utilization, high transmit/receive rates, etc. I would like to receive an alert when a condition like this exists.
Is there a way to get an alert on these kinds of events? The primary mechanism for alerts seems to be based on SNMP traps from the WLC to Prime. My 5508 (on v7.2.111.3) GUI shows the following for AP traps, which is limited:
AP Register, AP Up/down, AP Authorization. It also shows some very limited client events like Client Association, Client Authentication.
David

Client Count vs. Performance

Hello everyone.
I'd like to know your experience regarding how client count affects performance.
What I have seen in a university network, with a very high client densiity, using 3500 APs, is that around 55 clients ping reply time gets over 200 ms; around 60 users there's packet loss; then, as CC increases, somewhere between 60 - 70 the service gets totally lost. Off course, this depends on bandwidth consumption per user, interference, etc.
Also, I'd like to know what we could expect from 802.11ac regarding this topic. Is there any information on tests, or some estimation already published?
Thanks. And sorry if my enghlish is not good enough.

Julio,
Welcome to CSC.
I agree with Scotts statement. Although 802.11ac will allow clients transmissions to trigger at a faster PHY, it is still half duplex. Also, 802.11ac will need to be backward compatible to 802.11g and so on. Unless you have a full 802.1ac environment, your performance will suffer from backward compatibly support.
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

Cisco WCS client count report - client count figures cumulative or concurrent?

Hi,
Just want to clarify the "assoicated client count" and "Authenticated client count" values from WCS Client count report concurrent or cumculative?
The client count report in excel format:
Total Client Count
Total Count
Event Time
Associated Client Count
Authenticated Client Count
total
Sun Oct 12 23:59:59 HKT 2014
3992
3854
total
Mon Oct 13 23:59:59 HKT 2014
7838
7289
total
Tue Oct 14 23:59:59 HKT 2014
7724
7124
total
Wed Oct 15 23:59:59 HKT 2014
6849
6336
total
Thu Oct 16 23:59:59 HKT 2014
5908
5530
total
Fri Oct 17 23:59:59 HKT 2014
1240
1228
total
Sat Oct 18 23:59:59 HKT 2014
1040
1031
Client Count
AP Name
Base Radio MAC
Event Time
Associated Client Count
Authenticated Client Count
AP-EDHB-018
08:1f:f3:23:23:10
Mon Oct 13 23:59:59 HKT 2014
160
157
AP-EDHB-018
08:1f:f3:23:23:10
Tue Oct 14 23:59:59 HKT 2014
121
120
AP-EDHB-018
08:1f:f3:23:23:10
Wed Oct 15 23:59:59 HKT 2014
95
95
AP-EDHB-018
08:1f:f3:23:23:10
Thu Oct 16 23:59:59 HKT 2014
94
94
AP-EDHB-018
08:1f:f3:23:23:10
Fri Oct 17 23:59:59 HKT 2014
6
6
AP-EDHB-018
08:1f:f3:23:23:10
Sat Oct 18 23:59:59 HKT 2014
3
3
AP-EDHB-019
08:1f:f3:23:24:30
Sun Oct 12 23:59:59 HKT 2014
38
38
AP-EDHB-019
08:1f:f3:23:24:30
Mon Oct 13 23:59:59 HKT 2014
113
110
AP-EDHB-019
08:1f:f3:23:24:30
Tue Oct 14 23:59:59 HKT 2014
110
109
AP-EDHB-018 have 160 assoicated client count reported. Really mean there were 160 wireless client assoicated at a moment or there were a totally 160 connected at that day?
Any idea?
Dick

Hi Kayle,
Thanks for the response. I think you are talking about this in the above.
Reports > Report Launch Pad > Client > Client Count > Client Count Report Details
then
AP by Floor Area and select "All Campus", "All Building", "All Floor"
By doing this I get 700+ APs daily client count in graphical (pdf) view and need to go through manually each graph to identify the top 50, top 100 in a given day.
Is it possible to only filter the top 50, 100 APs ?
I would like see my daily report gives something similar to the below
AP Name    Max Client Count
AP01               96
AP02               83
AP50               20
Would it possible to get something like this from WCS reports ?
Thanks
Rasika

AP Reported channel utilization in Prime does not match reported channel utilization in Spectrum Expert

Hello
I have a fairly dense Wireless network with an Accesspoint per room. The 3502 models are connected to WiSM with Software 7.0.240.0 and are managed with Prime Infrastructure 2.2 (the issue was also in older PI versions).
PI reports on the 802.11b/g/n interface a channel utilization of 32% with a RX and TX utilization of 0% (no clients are connected to this AP). If I open this AP now in Spectrum Expert (thanks to CleanAir), I have a channel utilization of less than 5%, no interference power at all. Also the Swept Spectrometer is only showing signal with less than -85dbi (with a few very rare higher powered specks).
So which value is now correct, or do they show something different?
Thanks,
Patrick

This is very important to understand. I should actually do a blog post on the subjey, it comes up often.
Think like a wifi radio. You can only do 3 things: send, receive, listen. And you can only do one of these at a time. While in listen mode, you hear other traffic on your channel within range. In send mode you tx data on the channel. In receive mode you Rx data on the channel. Based on these functions. You as an AP can determine how often the medium (channel) is busy or not.
Lets go a bit deeper. Before a frame is sent a preamble is triggered to sync all clients on the channel. These client do not know yet if the frame is for them or not. Then the phy header comes telling clients how lomg/time the frame will take to send. Then the actual frame gets punched and all the clients receive it. The client brimg it up from the PMD layer to the data layer. Look at the Mac address and if its for them they process the frame. If it's not for them they drop it. But before they drop it they peek at the Nav timer in the duration / ID field and back off again. This time for the SIFS and ACK. This busy time calculates the number you are seeing .. Better ?
I normally dont don't worry about channel utilization till 40% under load. If you are at 40 without load I bet you habe 1 PHY mandatory .. Do you ?

Cisco LWAP client count concentration

Hello
I have an environment of Cisco 5508 Wireless Controller and 1142N Access Points. I have a problem with the ratio of concentration of clients connecting to Access points in floors.
Recently I have been turning off 802.11a on the access points and I am seeing increase in client count in a few of acces points.
Here is the snapshot..
What is the maximum client count supported by these access points and how do i ensure they are distributed evenly on access points?
thanks

Can you elaborate on your intentions again?
You are saying that you are shutting off A radios (5Ghz) and expecting to improve the performance of 2.4Ghz?
Generally speaking, the more you move off of 2.4Ghz toward 5Ghz, the better your 2.4Ghz performance will be (less is more). If you have any dual-band clients, most people would be looking to get those clients onto the 5Ghz (A) Radio which is where the Band Select feature comes in to play....
I guess I'm just not following the logic of disabling 5Ghz radios....
If you're trying to improve performance, I'd chose Band Select over Load-Balancing, in an attempt to move clients over to 5Ghz. If your clients are only b/g/n (2.4Ghz) then thats a non issue, and load-balancing would distribute clients across the APs but it comes with an expense of potentially slower roams...

Generate Prime Interface Availability and Utilization Report for unified APs

Hi,
I´m trying to generate interface availability and interface utilization report for unified APs on Prime Infrastructure 2.0, but it doesn´t display any information. I have created device health and interface health templates under desing/Monitor configuration/My templates and deployed under Deploy/Monitoring deployment, but it still don´t show any information,
thaks for your help.

Hi Alejandro,
Did you solve this problem? Or is it a bug?
I face the some issue with you, I just run "Report/Report Launch Pad/Deivce/Interface Utilization"
and then I create a report for interface utilization.
But it display nothing when the report run finished.
I ask some guys in this forum, they said maybe it's a PI2.1 bug.
BR
Frank

WCS Client Count Report without Map

I have a large campus with a large number of odd shaped buildings for which we do not have accurate floorplans and we need to run historical reports for the client count per AP however as far as I can see this is not possible unless I create maps and floorplans of the site.
Is there any way to get the client count per AP on a historical basis without the need to create maps and floorplans of the whole site.

It's been a while since using WCS, but I've always used maps. I would just suggest you add a fake map even if it's a box and place the AP's on the appropriate floor if possible. An old map is better than no map to be honest. I have had to take the emergency floor plans (old as heck) and copy that or take a picture on my phone and use that on WCS.
Sent from Cisco Technical Support iPhone App

Wired Client Count - Infrastructure 2.0

Hi all.
Im getting wired client count on the switche but im not getting the count on coverage area ect ...ive added the switches to location site. Anyone with the same issue ?
Im getting the total wired / wireless count in general view
I want a view with client count wired / wireless on location basic ( just like the Coverage view )
Filip

Hi Markus,
From my experience PI2.0 has very limited (basically none) custom reporting. The only customising you can do is with existing/preconfigured reports in terms of setting the dates, nr of devices reported on etc etc...
Lets see what the newer versions brings...
Ciao
JC

Setting Minimum RSSI threshold for client connections

Hi,
We are deploying a new wireless network for guest users of private lounges at airports, using a 5508 WLC and 3501 AP’s. The SSID uses open L2 authentication with a web auth passthrough login splash page.
We require preventing people outside these private areas to connect to the SSID, and we would like to do so by only allowing clients to connect if they exceeed the minimum RSSI guaranteed in the private areas (i.e. prevent connections below a certain level, such as -70dB). We tried to configure this by settings several parameters, for example the “Minimum RSSI” under “Client Roaming” without achieving the desired effect.
Can a minimum RSSI be set up so clients would not connect unless they receive the minimum specified signal level? If so, can anyone please advise how to set this up?
Many thanks in advance for your expert advise…
Regards
Luis A

This one is an idea (but costly): Faraday cage (aka Faraday mesh or Faraday shield)
If installed correctly, your wireless signal will be inside the four walls (don't know if you have those glass doors but if you do ...).
Out of curiousity, WHY did you purchase 3501 instead of 3502?
I mean 3501 means it only has 802.11b radio. And 802.11b is long range and high penetration rates compared to 802.11a radio.
Lower the PHY rate ... 1 meg PHY rates travel VERY far. If you disable 1,2,5,11,-- all the way up to 24 or so .. you will need to be right on top of the AP. 20 feet or so..
What about clients with old portable devices? That's a risk.

Setting the Client Count per WLAN and per AP radio

Hi
We use WLC 5508 with 7.4. We tried to set max allowed clients per AP radio to 30 through GUI. We have APs with 80 clients associeted though.
Has anyone else tried this feature?
When entering config wlan max-associated-clients max-clients wlan-id we got
"WLAN/Guest-Lan/remote-lan is enabled.Please disable to configure max associated clients."
GUI doesn't show that message, should it? In GUI, Is it necesary to disable WLAN before too?
Thanks
This is the show wlan output

No, the GUI does some stuff automatically, like disablen/enabling the WLAN when you make the change.
From teh CLI *you* have to do them.
HTH,
Steve
Please remember to rate useful posts, and mark questions as answered

Trouble with channels and clients using different 802.11 g/n adapters

Hi,
I have moved to a new home and I have a lot of problems with the wireless network
I have configured the airport extreme to use the "802.11n draft" with backward compatibility to b ang g at 2,4 GHz.
I had to manually select channel because the "Auto" option will probably use channel 6 and in this way all my clients are unable to connect.
After many tests I have found that I cannot use channels from 4 to 9 because my macbook airport card will not detect the wireless network. Channel 1 seems to be the best choice but it is used by other people in the near homes also.
With channel 1 my macbook is able to connect and mantain a stable connection, the signal is about 35%, unfortunally other clients (using windows XP, broadcom wireless adapter or a d-link DWA-140 USB key) are unable to have a good and stable connection: it is always "low", "very low" or not available
Using the D-Link DWA-140 wireless config utility I have discovered today that channel 5 seems to be the better for such device: using channel 5 it is able to connect windows clients from everywhere with good or excellent signal BUT my macbook wireless results completely dead instead :-/, the same for broadcom client.
D-link is unable to connect if I set channel 6 to 9 also.
Macbook is unable to connect to 5GHz 802.11n pre-standard, D-Link is able instead.
I have no cordless phones or running microwaves in the kitchen, the only thing I have is an home alarm using infrared and microwave sensors in each room. But they told me that they are using a frequency range much different from 2.4 GHz. Unfortunally I am unable to completely power off them and test some more.
May be that near homes have cordless phones, wireless routers or video/audio repetitors, I don't know. I also have much iron in my walls. It is very strange that d-link can use very well channel 5 while other wireless cards/clients are unable to find any network there.
I am going to become creazy... if I was able to explain the situation, could anybody help to investigate some more or try to solve?
thanks a lot in advance!
Fabio

may be I have found the cause of all these troubles: the alarm motion sensors installed in each room.
I have made a search in the Internet and I have found the technical details of my sensors: microwave tecnology used by them is exactly using the frequency of 2.45 GHz :-/
So I have moved outsite of my hause the Airport Extreme and notebooks to confirm my suppose:
all channels were perfectly working, "auto channel" selection was ok, macbook was able to connect at 5GHz 802.11n mode. Windows client was ok too with all wireless cards or USB devices.
The alarm sensors seem to be always active and seems not possibile to have them completely off when the alarm is not activated.
I think I am going to switch them to a different version that does not use 2.45 GHz microwaves.
It seems the solution to my troubles.
Hopes this helps somebody else.

RSSI, channel utilization, clients counts on APs

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