Load Balancing for APs

[gregniemeyer]

I am thinking about turning on Load Balancing on our Cisco 5508 controllers.  At times...we have 40 - 50 plus clients connect to one AP.  I am still researching this.  Are there any gotchas that I should be aware of?  This is a large school district and we have about 12 campuses with over 300 APs.

Thanks,

Greg

[Saurav Lodh]

Aggressive controller( limited the controller,  load balanced across different APs )

http://www.cisco.com/c/en/us/td/docs/wireless/controller/7-4/configuration/guides/consolidated/b_cg74_CONSOLIDATED/b_cg74_CONSOLIDATED_chapter_01000.html

[gregniemeyer]

If there isnt another AP close after the client fails.....will it still try the original AP?  I dont want to shoot myself in the foot when I turn this on.

[abwahid]

Hi,

You can configure the controller to deny client associations up to 10 times (if a client attempted to associate 11 times, it would be allowed to associate on the 11th try). You can also enable or disable load balancing on a particular WLAN, which is useful if you want to disable load balancing for a select group of clients (such as time-sensitive voice clients).

[George Stefanick]

I don't recommend it. Most client won't honor reason code 17 and will

still attempt to join an ap who says go away. Your best bet is to design your coverage with more apls to support the load .. 

[Stephen Rodriguez]

if you have any applications that are time sensitive i.e. Citrix or Voice, I wouldn't recommend that you enable this feature.

All this feature does is try to influence the client to join another AP by sending a message type 17. On the 4th attempt of the client to join the AP, it is allowed on. If you have time sensitive applications, this can cause them to drop their connections.

Remember that it is the clients decision on what AP to join, and when to roam.

HTH,

Steve

[gregniemeyer]

Mostly Ipads and Iphones.....and some laptops.  The problem I am seeing is.........classroom full of students with phones that connect.  Lets say two classrooms are closest to one AP.  That's gonna put 30 to 40 connections on that AP....then the teacher rolls in a cart full (25 to 30) of laptops that need to connect.  Now it's up to 50 + connections......or more.....

[Stephen Rodriguez]

Honestly at that point I'd go a little more low tech...

Put the schools SSID that the laptops will connect to on 5GHz

Put the "guest" SSID that the students personal devices connect to on 2.4GHz

then you don't need to worry as much. Each AP may have 50+ clients but the per radio usage is lower.

HTH,

Steve 

[gregniemeyer]

That would not be an option for us.  We need to have only one that is open.  Password issues.

Hypothetical scenario.....Load balancing turned on.  Only one AP in a building...but there are many APs with the WLAN in another building not in reach.  Would the one AP reject clients.....if one of the other APs not in reach were less busy?

[gohussai]

Check the following attach document for your query.

Hope this will  be helpful

[patoberli]

Last time I tried aggressive load balancing at my school infrastructure it was horrible. It's some 2-3 years ago though, but I haven't seen much progress in the software.

Mostly Apple clients decided to fail to connect at all. They wouldn't connect for several seconds up to several minutes! I had to disable the feature.

Modern APs like the 2700 series can fairly well handle up to 100 clients simultaneously, but it depends a lot on the traffic requirements.

Here I often have 50 clients connected to a single dual-band AP (3502i or 3702i)  and I'm not getting any complaints that it's slow or unstable.

Also check this: http://nostringsattachedshow.com/AP2700/Cisco_AP2700_Multi_Client_Test.pdf