How do I improve 802.11n connection speeds?

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I have an AP330 in my lab, I have been comparing it to a cheap Edimax AP that costs less than a quarter of the price. I have a couple of 802.11n compatible clients, both only support 2.4GHz, however one client will connect to the Edimax AP at 300mbps while the other will connect at 150mbps. What I don't understand is that the same clients will only connect to the AP330 at 144mbps and 65mbps respectively.

I've created a new radio profile, set preamble to auto, enabled short guard interval, set the channel width 40MHz below, manually set the channel to 6 (as inSSIDer shows this to be clear), but still no luck.

Surely an enterprise grade premium AP like the 330 is going to be superior to a cheap as chips Edimax AP, so why is it failing to match or beat it in a simple link speed connection test?

I must be doing something wrong somewhere. My hive is running 6.1r3.

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Call Eva

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Posted 4 years ago

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Andrew MacTaggart, Champ

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Note: Only AP120/110/170/320/340 11ng mode support Channel Width 40-MHz above, 40-MHz below, other platform just support 20 MHz.

most organizations would not use 40MHz channels in 2.4Ghz

but suppose for home use or lab it would be ok, but the clients maybe intolerant

the 802.11n standard has a feature to advertise “intolerance” for 40 MHz operation to the infrastructure. But for your case you have the wrong AP.

(Edited)
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Lexxington

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Yeah Nick..all fine with u and ur writings... :-) 
I'm confused about Andrews post above that the AP230 does not support 40MHz and I wanted him to correct his post or tell me if Im wrong or missing some information.
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Nick Lowe, Official Rep

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He copied the top line in his post from HiveManager. It was Aerohive's wording at the time. Things change. It doesn't pertain to the AP230 where TuboQAM is in use.
(Edited)
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Lexxington

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Ahhh there we go...So we do not have software/driver support from aerohive atm. Thats bad. OK, but thnx anyway!
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Nick Lowe, Official Rep

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I didn't say that! :P TurboQAM is supported by HiveOS actually, disabled by default.

I would never use it, however, as it's non-standard, Broadcom vendor specific behaviour and precises because it uses a channel width > 20 MHz at 2.4 GHz.

I don't think it has a place outside of home users personally, if at all.

You're reading far too much in to this! :P
(Edited)
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Lexxington

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No...I do not want to use it either. I just want to state clear that the AP230 does support 40MHz. Not more and not less. :-) 
We have 8 AP230 inhouse and most laptop have 2x2:2 wifi chips onboard. more that 130Mbps is not possible - but for office work thats more than needed. :-)
All fine here ... just wanted to clarify.
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Nick Lowe, Official Rep

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Like Andrew, I certainly would not today touch a 40 MHz channel width at 2.4 GHz outside of the lab or home setting either due to:

  1. Client compatibility issues.
  2. Insufficient spectrum when you have more than 1 AP with overlapping coverage.
  3. Interference issues with other neighbouring networks.
As Andrew points out, HiveManager states for a radio profile at 2.4 GHz:

"Note: Only AP120/110/170/320/340 11ng mode support Channel Width 40-MHz above, 40-MHz below, other platform just support 20 MHz."

The argument that such a configuration should be abstractly possible on all HiveAPs if wanted is, prima facie, valid. However, given Aerohive's target market it has little to no use in the real world for the expected use cases of their customers.

Honestly, if you want higher throughput, you should change your client hardware and switch to 5 GHz.
(Edited)
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Call Eva

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Ok I understand the reasoning, target market is probably the best one, I was just a little surprised that a home/SOHO AP could potentially offer higher throughput than an enterprise grade AP. Will need to bear this in mind for people doing POCs/trials etc. who are comparing with what they have at home, when they should really be comparing with other enterprise grade solutions.
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Nick Lowe, Official Rep

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The important point to make is that it is generally bad practice to use a 40 MHz channel width at 2.4 GHz. By not offering this as it serves no purpose in Enterprise-class deployments, it stops people from hanging themselves via something that could easily sound, at first sight, to be a good thing and get casually configured without realising the negative implications.

It is only the older generation 802.11n Aerohive APs, mostly discontinued, that support such an operation. I am actually somewhat surprised that it has not been withdrawn completely in the newer HiveOS releases.
(Edited)
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Crowdie, Champ

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I am going to play the devils' advocate (if only because I am very good at it) and raise the following points:

  • "Speed" and throughput are two very different things in the wireless world.  The "speed", as reported by wireless clients, is the data rate the wireless client thinks it can transmit at IF it can get access to the medium.  Throughput is a measure of actual TCP data passing through two points.  Therefore, you should always use throughput as a measurement of performance not "speed" (basically a data rate).
  • The utilisation of 40 MHz wide channels in the small 2.4 GHz spectrum will result in increased wait states for a wireless client (assuming the access point is in a real world situation and not in a concrete bunker 100m under the ground) that will not be shown in the "speed" value but will appear in a throughput test.
  • Basic access points are really just media converters and don't have the overhead of advanced QoS, etc.  For this reason a single wireless client connected to a basic access point will commonly, in my experience, perform better than when connected to an enterprise access point.  However, put four more wireless clients, each streaming 1080p video, onto the same basic access point and the each wireless client's throughput will drop through the floor while results for the same test on the enterprise access point will not display the same drop in each client's throughput.
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Crowdie, Champ

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As the Aerohive access points have an inbuilt iPerf engine you can SSH into the access point and use a command like iperf client <iperf server IP address> udp dual-test time 30 while on the Desktop PC you can run the JPerf network performance measurement tool (the latest version I could find is 2.0.2) using a command like bin/iperf.exe -s -u P 0 -i 1 -p 5001 -f k.