Where is the right place to set a limit for 2Mbps for Ipad

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I have been looking at a nice video where Devin Akin explain problem with a lot of Ipad in a classroom . We have one accesspoint(AP370) per Classroom. Devin saying that 2Mbps per Ipad is enough. I am new to Aerohive so please where should I configer this limit to 2Mbps per Ipad.
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Jan Boje

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Posted 4 years ago

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Andrew MacTaggart, Champ

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I would say no need to limit anything. contention will limit by itself. You should try to get your clients on and off as quickly as possible. I assume you have IPADv2. you may want to do client load balancing between 2.4GHz radio and 5GHz radio.

I can tell you that we urge clients to join 5GHz and have 30 IPADs v2 connecting to AP 330 with minimal issues, but it really depends how the IPADs are being used.

the newer IPADs will have 2 streams and support 40MHz channels + SGI etc...
here is what the wifi alliance cert for IPAD air
2.4 GHz, 5 GHz - Switchable
Tx 2 tested Spatial Streams 2.4 GHz
Rx 2 tested Spatial Streams 2.4 GHz
Tx 2 tested Spatial Streams 5 GHz
Rx 2 tested Spatial Streams 5 GHz
Short Guard Interval
TX A-MPDU
40 MHz operation in 5 GHz
HT Duplicate (MCS 32)

There is so much more to the puzzle
AP 370 - are you using 802.3at -some of the 802.11ac features will be disabled if using 802.3af

how are you using the AP370's
what is the distance between APs
are you using 80MHz channels
do you have any clients that are 802.11ac
what is your channel plan like, are you using DFS channels, do the clients support it. Available channels depend on the country you are in.
What power level are the radios at?
have you disabled the lower data rates for b and a radios

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Jan Boje

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Thanks for the answer. 
Yes we have only Ipad2 and they are using it with a LOT of video. The accesspoint is very busy.
At the moment we urgy the client agains 5 GHz. I think that we will set up load balancing between 2.4 and 5GHz for the client. 
We got one accesspoint in every classroom, we are only using 20 MHz
When we have the problem it was on channel 40 so now problems with radar. We got a lot problem in other schools with radar, but on this school we have no radar problems.
Power level is on auto. same as channels.
lower data rate is disabled and B- is "dead".

mac and pc is working well, just the Ipad2

I would stil like to know where to set limit for 2Mbps
 
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Andrew MacTaggart, Champ

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I would need to see Devin's video to understand what he is talking about
I assume it is this video
http://blogs.aerohive.com/blog/wi-fi-that-wont-die/wi-fi-design-for-ipad-deployments-in-k-12

when you configure your network policy
2 - Configure Interfaces & User Access
look for additional settings towards the bottom
there you will find air time scheduling
under qos settings

but I think your problem is more of a contention issue

I would say bring the radio power down
and turn on airtime fairness or dynamic airtime scheduling
disable some of the 2.4GHz radios
disable the lower datarates
make sure that each AP can only hear neighbors that are -85dBm or less[ this means -86 dBm,, etc...]  in the same channel

My friend Marlon did some throughput testing with 20 ipads all running video

https://www.youtube.com/watch?v=OSZt_BD4YB4

have you read Andrew's excellent document

http://www.aerohive.com/330000/docs/help/english/documentation/Aerohive_High-Density_Wi-Fi-Design-Co...




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Jan Boje

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yes it is this video with Devin. Nice video from Marlon.
I will take a look at the Network Policy
Hope you will be back when you have seen Devin's video.
Thanks
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Jan Boje

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I forgot i have read Andrew's document
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Nick Lowe, Official Rep

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Honestly, you most likely do not want to attempt to do this. It is not at all the right thing to do in the vast majority of use cases.

What observed problem are you trying to solve?

You nearly always want airtime fairness and sufficient capacity, not absolute limits.
(Edited)
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Brian Powers, Champ

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Jan,

With that many APs, I'd suspect your channel utilization is quite high.  And you could possible benefit from disabling a few more lower data rates (6, 9, and even 12 possible). 

Also, do not confuse load balancing and band steering within the radio profile.  Band steering will "urge" clients to one band or another upon association time.  Load balancing will move clients to other APs, possibly APs with a weaker signal than their current AP and could cause more issues than it helps.  I only use load balancing in extreme high density areas (conference rooms, auditoriums, etc.  Places where you have multiple APs that all users see pretty equally. 

A few commands you can run to see some channel overhead from the APs.  From the CLI prompt you can do the following:

show acsp neighbor - this will show you what other APs this particular AP sees and at what RSSI level.

show acsp channel detail - this shows a breakdown of how the AP determined the channel it is currently using and the values of the other channels

show acsp channel - this shows an abbreviated brief cost of each channel based on the above commands details



Without setting the "Channel Auto Selection" in the radio profile, the APs (in my experience) will seldom move to a more appropriate channel (outside of some sort of major interference).  A reboot will trigger this however.

I'm in agreement with the folks above, that limiting bandwidth should not be used unless absolutely necessary.  But if it is desired,one option is configured under the User Profile assigned to the SSID and in the QoS Settings -> Rate Control & Queuing Policy.


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Jan Boje

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Thanks for your answer, I will try and test now,