AP370 performance issues with OPEN wifi, and 802.11ac

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  • Updated 3 years ago
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Hi there, I'm hoping someone can give me some advice or point me in the right direction.

We recently bought 6x AP370s to replace the previous wireless we had for the office. The problem we've had since day one is terrible performance with Open (guest) wifi and 802.11ac throughput.  With the guest wifi, what I'm seeing is users will get a DHCP address however there looks to be too much contention as users are seeing their connection drop. I'm only seeing a maximum of 30 users on a single AP; I wouldn't have thought numbers this low would be an issue.

There is also a throughput issue with 802.11ac.  I'm seeing throughput of 20-30mbps, which is no where near what I'd expect for 802.11ac. From the wifi status page I am seeing the message "high tx error" however nothing I've tried so far has helped.  I've used a spectrum analyse tool, however that didn't give me anything useful.

My feeling is that we've gone a little OTT with the AP placement.  I've tried to compensate for this by alternating SSIDs on the APs which has improved things a little.

I'm using the most recent version of HiveOS - 6.0r2f.  I've searched previous community forum posts, however I haven't come across any that have a clearcut diagnostic chain. 

Any assistance is greatly appreciated.

What I've done so far:
- Lowered the transmit power to 11db - though I think I may need to go lower to improve performance. I'm just concerned with coverage in some areas.
- Due to merging with another company, for now we have the need for 6 ssids :(  I've managed to split these SSIDs across the 4 WAPs on one level. However the 2 APs on the lower level have all 6, however this is more of a design problem which I'm working on.
- I've disabled 802.11b clients in the radio profile
- Turned on some High density settings
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Aaron Christensen

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Posted 3 years ago

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Crowdie, Champ

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If you turn off the radios on one of the access points does the transmit error rate on the neighbouring access significantly drop?

If you run the show acsp neighbor command on one of the adversely affected access points what channel utilisation levels are shown?  If they are above 30% then you are going to experience performance issues.

I would also try the following:

  • Reduce the numbers of SSIDs to four or less.
  • On the radio transmit power levels I recommend levels around 15 dBm as this seems to be the best transmit power level for smartphones and tablets.
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Dawn Douglass

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High TX retries could be due to numerous things but, the two that come to my mind first are low SNR and the number of SSIDs.  I know that you said that you are trying to spread the SSIDs out between APs but the traffic created with each additional SSID is staggering.  See Andrew Von Nagy's chart on the number of SSIDs as related to channel consumption.  How about utilizing user profiles to cut down the # of SSID's to just a couple?

Also, I have seen 30 clients overwhelm an AP 121 and 330 and produce the symptoms you describe.  In fact, I have seen it with a few less than 30 clients when the clients were requesting a lot of airtime.  
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Crowdie, Champ

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Are the transmit errors worst in the 2.4 GHz spectrum?  If so, have you tried setting a 2.4 GHz radio maximum transmit power of 15 dBm and disabling every second or so 2.4 GHz radio?  If you reduce the maximum transmit power too low you will replace the transmit errors with receive errors.