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Beginner

recommended number of Users per AP (AIR-CAP2602I-E-K9)

Hi, is there a recommended maximum amount of users per AP? couldn't find such a parameter in the data sheet and noticed that load threshold on WLC is set to 12 clients

 

 

thanks,

KR rena

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Hi Rena,

The channel utilization is the sum of three values: Rx, Tx and Broadcasts on the channel. So, in this case , as we can see that the Tx utilization is 7% but the overall is 38%. This clearly indicates that there may be some noise/traffic on the channel on which the AP is working at that moment.   

It would help if you can get the output of "show ap auto-rf 802.11b/a <ap name>" for this AP. This will show you all the neighboring APs working on the same channel on which this AP is working. If there is any other AP being heard on the same channel with a strength of ,more than 65 dBm (example 63 dBm) , then you may have co-channel interference in the network.

As far as the number of users are concerned , 25-30 was the recommended numbers in the generation on Non-802.11n autonomous APs. Today, the 802.11n capable APs are tested in lab with 200 clients associated  "PER RADIO". Thus, I would say, depending on various factors like interference in the environment, client applications in use, uplink capacity, local or central switching of the traffic , an AP may serve 40-60 clients with no major issues. Again, DEPENDS heavily on a lot of factors. I have just mentioned the capability of the new APs.

 

HTH, Cheers,

Manish Mathur 

 

View solution in original post

20 REPLIES 20
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Participant

this is a threshold trap , it will not restrict the client number per AP , 

i recommend to use load balance and enjoy it .

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yes I noticed that this is just the snmp threshold for traps indicating the AP is overloaded, but I was wondering how cisco came up with that value of 12..is it a recommended amount of users which should be associated to an AP? Of course this depends on how much bandwidth every user should have, but right now it's hard to measure this since I didn't find a way to check how much bandwidth would be left on a channel =/

Are you using the load balancing and band select features? Do you have experience with that? I read that load balancing is often not working, because there are a lot clients, which simply ignore reason code 17, but I would give it a try, if I could somehow evaluate the right client window size...
 

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you are right so this is why you can see utilization percentage (which will represent the bandwidth) as well not only client count , 

 

the load balancing is recommended only in the high dense deployment , since the MAX client count is concerning you then i'm considering that you have high dense site , 

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do you happen to know how LAPs estimate channel utilization? I couldn't find anything in the manuals.. It's strange that rx and tx are low, but the CU is at 38%

we're using wlan instead of lan so the density is as appropriate.. my goal is to find out if we have enough APs and if there is some potential for improvement, so I went through all the reports which are available with prime infrastructure and this is how I started questioning those predefined thresholds..

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channel utilization is different than Rx and Tx utilization , 

channel utilization include interference , noise and the connected clients traffic load .

 

Highlighted

Hi Rena,

The channel utilization is the sum of three values: Rx, Tx and Broadcasts on the channel. So, in this case , as we can see that the Tx utilization is 7% but the overall is 38%. This clearly indicates that there may be some noise/traffic on the channel on which the AP is working at that moment.   

It would help if you can get the output of "show ap auto-rf 802.11b/a <ap name>" for this AP. This will show you all the neighboring APs working on the same channel on which this AP is working. If there is any other AP being heard on the same channel with a strength of ,more than 65 dBm (example 63 dBm) , then you may have co-channel interference in the network.

As far as the number of users are concerned , 25-30 was the recommended numbers in the generation on Non-802.11n autonomous APs. Today, the 802.11n capable APs are tested in lab with 200 clients associated  "PER RADIO". Thus, I would say, depending on various factors like interference in the environment, client applications in use, uplink capacity, local or central switching of the traffic , an AP may serve 40-60 clients with no major issues. Again, DEPENDS heavily on a lot of factors. I have just mentioned the capability of the new APs.

 

HTH, Cheers,

Manish Mathur 

 

View solution in original post

Highlighted
Beginner

Hi Renata,

This is one of those 'it depends' type questions. There are countless variables that determine how many clients a given AP can handle. It's all about how much airtime is available within an AP's cell.

Client type, application use, enabled data rates, encryption types used, co-channel/adjacent channel interference levels (or cell SNR levels).

Assuming a 'clean' or optimised RF environment, many manufacturers recommend around the 25-30 client limit with an 802.11n capable AP.

-Brett

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Enthusiast

In Simple words and as per Cisco recommendations .

 

The Average user per AP should not exceed 25.

 

 

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Beginner

This FAQ which was published in 2010 when we probably only had 1252 as the AP supporting 802.11n  :

http://www.cisco.com/c/en/us/support/docs/wireless/aironet-1200-series/8103-ap-faq.html

It says: "  The AP has the physical capacity to handle 2048 MAC addresses, but, because the AP is a shared medium and acts as a wireless hub, the performance of each user decreases as the number of users increases on an individual AP. Ideally, not more than 24 clients can associate with the AP because the throughput of the AP is reduced with each client that associates to the AP." ..

It's evident that after 2010, Cisco has launched advanced APs like 2602, 3600, 3502, 3702, 1702, 1572 etc.. All these APs have advanced memory and CPU capabilities. faster processors means more service. I hope you will be able to understand now that sky is the limit for "simple client association", but if you consider actual service, the number depends on a lot of factors as Brett has mentioned. In my organization , I see 60+ corporate clients associated and working without any complaints on 3702 and 3602.

 

Cheers,

Manish

 

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Enthusiast

Hi,

see the posts below

https://supportforums.cisco.com/discussion/11844466/how-many-clients-support-access-points-1602-2602-3602

https://supportforums.cisco.com/discussion/11718356/maximum-recommended-clients-access-point

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Hi guys,

I have a dense utilization area, fortunately an open space. I currently have installed a 2602i AP, but still receive complaints.

To make things better which of the two you recommend:

 - buy a powerful AP like 3700 or even bigger model; if yes what bigger model than 3700i can I use?

 - install a 2nd AP next to it (it has to be within 1m of the existing AP as this how ceiling cable is available).

 

Thanks,

Florin.

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Hi Florin,

 

An AP with internal antenna for an open space ?? Not a judicious choice.. 2602e with a good antenna choice should suffice for a dense deployment... Depending on the number of clients and the AP/antenna  deployment, you can deploy n number of APs to get the best wireless experience...

 

Cheers,

Manish

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Hmm, it's office interior open space. I though exterior APs are for outside.

So settling this to an interior space (no walls):

1. a powerful AP?

2. additional AP?

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Ohh.. Ok.. You are correct.. E APs are for external spaces.. I mistook open space as an external area...

I would vote for additional 2602 AP since for HD designs , it's recommended to have multiple APs with smaller cells rather than a single AP with large cell.

You can also refer to the high density design guide for further readings..

 

Cheers,

Manish