Wireless Access

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Occasional Contributor I
Posts: 6
Registered: ‎07-31-2012

Inexplicably Low goodput coupled with horrible performance

I just started an a loudspeaker design company based in China, their IT department is a bit inexperienced and really all they do is their best to make sure everything is kept working the way it was when the consultants came in an designed the network. Our wireless performance is absolutely horrible and I'm trying to get to the bottom of it. I've got root access to the Aruba 3400 AP controller and have done a bit of reading through its documentation as well as exploring the current configuration (which pretty much seems to be everything set to default).

 

We're really not a big company. We've got 14 Aruba 93 APs spread between 2 floors. We have about 200-250 clients on any given day and while China being China our 30Mbps internet often feels more like 56kbps, our intranet speed is pretty decent over wired connection. I'm kind of new to IT on the administrative level, but I offered to help because I unlike our IT dept. understand English, and have the motivation to make it better for our engineers.

 

It might be just me but when the controller is at .6% utilization and we only have 14 APs and 200 clients on hardware that supports 64 and 4000 there should be absolutely no issues. Alas, when I go into the potential issues section of the dashboard 14/14 of my APs are marked as low goodput (<24Mbps), I don't get how this can be, the whole network is gigabit, the clients are almost all N or as this seems to call them g-HT. At first I thought maybe it could be interference, and I've messed with the ARM settings a bit, changing to "mode aware" and multiband, but no such luck. I don't really get how to change the band from 2.4 to 5, or really I mean dual broadcast, but I'd like to try that if possible.

 

This whole thing is a real headache and having never really administered a network before, I'm having trouble understand how our $12,000 worth of equipment can't do what I'm will to bet money on my $100 buffalo router can do. (And I mean it, I've set up two or three of these in bridge mode throughout the offices, and people use them with speed on par with that of the wired network.).

 

Any help would be greatly appreciated. 

Cheers,

Dan

Guru Elite
Posts: 20,821
Registered: ‎03-29-2007

Re: Inexplicably Low goodput coupled with horrible performance

Please look at the top 10 tips from Aruba TAC here:  http://community.arubanetworks.com/t5/Community-Knowledge-Base/Top-10-Tips-from-Aruba-TAC/ta-p/29414

 

- How many WLANs (SSIDs) are you broadcasting? - (over 4 could degrade performance)

- Do they all have "drop broadcast and multicast" enabled? - (improves performance)

- Do your WLAN clients share a layer 2 subnet with wired traffic? - (can really degrade performance)



Colin Joseph
Aruba Customer Engineering

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Contributor II
Posts: 40
Registered: ‎12-16-2011

Re: Inexplicably Low goodput coupled with horrible performance

If you are troubleshooting "speed" issues I would also suggest running something like iperf to a wired endpoint off the controller. That way you can test the actual speed of the WLAN rather than working with the perceived speed of the WAN. This way you can also see if your changes are actually helping.

 

Low goodput also doesnt mean that there is really an issue. If the clients arent sending more than the threshold for that value (i think 24 Mbps) you will see that message.

Occasional Contributor I
Posts: 6
Registered: ‎07-31-2012

Re: Inexplicably Low goodput coupled with horrible performance

Hi, thanks for the advice. So I set up a computer running iperf server connected directly to the controller. Then I ran iperf from a wireless client and recorded the first result. Then I tried from a wired client and recorded the second result.

 

Wireless_Client_to_Controller

Wired_Client_to_Controller

 

It seems to me that this definitely narrows the issues down to something between the APs and the Controller and not the rest of the network (like I said the wired network is usually fine). 

 

And I understand low goodput can not be an issue but I feel like because its so much lower than the throughput and our performance is so bad, it must be relevant.

 

Screen Shot 2012-08-01 at 2.28.47 PM.png

 

Does any of  this info show any glaring issues I might be missing as a newcomer to administration?

 

Thanks,

Daniel

Guru Elite
Posts: 20,821
Registered: ‎03-29-2007

Re: Inexplicably Low goodput coupled with horrible performance

Yes, the iperf test is going to be much lower on wireless than wired because:

 

- Wireless is a shared mechanism and no two clients can transmit at the same time, on the same VLAN in the same system

- Wireless has a much lower top rate than wired

- Wireless transmissions are very inefficient vs. Wired Transmissions

- The more wireless clients you add, the lower the throughput

 

With that being said, you have to determine:

 

- Is the throughput too low?

- What is causing the issue?

 

You should measure the iperf test after hours to see your maximum throughput with nobody on.  That should be your baseline, and nobody elses.

You should ensure that wired and wireless clients are not in the same subnet, because the wired clients will create additional unicast and broadcast traffic that wireless clients will back off from.

You should look on the dashboard to see if there is any interference on access points or the noise floor is in the amber or red regions.

You should also look at dropping broadcasts and multicast at the Virtual AP level if wired and wireless clients must be in the same subnet.

 



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

Occasional Contributor I
Posts: 6
Registered: ‎07-31-2012

Re: Inexplicably Low goodput coupled with horrible performance

I understand that wireless is much slower than wired, and much less efficient. I'm trying to solve the problem of the throughput and goodput being so far apart. Is this a normal deviation? It's my understand this means there is a lot of interference and a lot of collisions happening.

 

I am trying to determine what's causing the issue. I enabled channel-based spectrum load balancing, and I configured ARM to be more aware, and disabled the a radio (these are single radio AP's so it wasn't being used anyways). There are 2 subnets being used for the wireless and they're being used solely for the wireless 10.12.70.xxx and 10.12.71.xxx, I have a fair amount of signal to noise ratios in the "red/amber" zone but my noise floor seems to be ok.

 

I'm beginning to think it could just be congestion. But it doesn't make sense to me, the max number of clients the APs have at any given time is 40 and the channel utilization is almost always hovering around 40%.

 

I've spent the last 3 days reading documentation and toying with the settings all to no avail. 

Guru Elite
Posts: 20,821
Registered: ‎03-29-2007

Re: Inexplicably Low goodput coupled with horrible performance

Please open a support case so that they can review your installation and troubleshoot ASAP.  There is a limit to what we can do on here, because we cannot ask you to  post important personal information that we would need to get to the bottom of the issue.

 



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

New Contributor
Posts: 2
Registered: ‎09-15-2011

Re: Inexplicably Low goodput coupled with horrible performance

Hi Daniel0524 and cjoseph & anyone who reads this comment. 

 

I'm a field System Engineer from an Aruba Networks partner in Mexico City, I have the ACMA, ACMP certifications, so I've made Design, Implementation & L2 support to Aruba Infrastructure across some companies.

 

So, I have the same problem that Daniel0524 has, Í don't know if there is a coincidence but I have these problem only in two projects using 600 series controllers with 6.1.3.X OS Version, both with mixed 105 & 135 AP's, (I've tried 6.1.3.4, 6.1.3.5, 6.1.3.6 & 6.1.3.7 OS versions with exactly the same problem).  In both cases I only had two SSID's (employee & guest).  Employee uses 802.1X, WPA2 Entreprise, AES, with external radius in windows 2008.  Guest uses Captive portal & Internal Database.  In both environments I use separate vlans for each SSID.  In environments who uses 5.X.X.X OS versions, all works just fine, no issues, whit exactly the same configuration.

 

I've made some research and apply all the recomendations from cjoseph, "drop broadcast & Multicast" separate vlans for wired & wireless clients, and other recomendations from cjoseph founded here in Airheads. but the problem continues.

 

Since I don´t administrate these 2 environments I didn´t open a case to Aruba TAC Support.    I only want to know if Daniel 0524 Open A TAC case & if Aruba Support solved his issue and how it solve it.

 

Thanks for your support & sorry if I wrote somthing wrong cause english its not my primary language.

Regards.

New Contributor
Posts: 2
Registered: ‎09-23-2014

Re: Inexplicably Low goodput coupled with horrible performance

Were you able to get this issue resolved? We are having the same issue and can't figure out what is causing it.

 

MVP
Posts: 1,412
Registered: ‎11-30-2011

Re: Inexplicably Low goodput coupled with horrible performance

hello Rich, this is a thread from 2012 and 2013, the chance your issue and certainly the cause is really the same as the guys above is quite small. i would advise you to start a new thread and explain clearly what the environment is (device, versions, ...) and what the speeds are you get.

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