We currently have 13 Unifi - UAP Pro AP's on our site.
I'm having an issue where around 10-15 or more laptops connect to our wifi everything starts to grind to a halt, there is very little bandwidth actually moving, it's like no devices are getting any Airtime. Transfer speeds drop to as little as 0-50Kb/s and we get latency spikes up to 3000ms & dropped packets. If I turn everything else off and run only a few laptops I get normal speeds.
The laptops in question all have Intel Wireless-N 7260 AP's (not capable of 5GHz).
All AP's & Wireless cards are on their latest drivers/firmware versions.
We need 30 laptops in total to be able to connect to one access point.
None of our AP's are close in proximity and they are split between channels 1, 6 and 11. I have tried setting them all to low power, I have tried Airtime Fairness and Bandsteering but nothing seems to be making a difference.
At the moment I'm leaning towards there being an issue with the network cards on the laptops but I don't have any other kit to test.
Any suggestions or help would be appreciated.
Do a site survey.
Free software to accomplish this;
Mac: use the built in Wireless Diagnostic or NetSpot Free https://www.netspotapp.com/
PC: Acrylic WiFi Home https://www.acrylicwifi.com/en/wlan-software/wlan-scanner-acrylic-wifi-free/ or the aforementioned NetSpot Free
Android: WiFiAnalyzer (open source) https://play.google.com/store/apps/details?id=com.vrem.wifianalyzer&hl=en
iOS: Unfortunately Apple hides the wifi chip behind the API and does not let apps have much in the way of data from the chip. In iOS 11 Apple won't even let apps have access to the MAC Addresses in the ARP tabel. You can use the Airport Scanner tool to find Wifi networks but you will not get the same detailed information as the other devices.
On the AP itself: In your controller go to Devices click on the AP you want to run an RF scan on, find the "RF ENVIRONMENT" section in the AP "Properties" pages, and click "scan".
When you do your site survey make sure you MOVE TO OTHER ROOMS! If your AP is dead center of your building it will be shielded by the walls and may see channel 6 clear, yet the room where you have a client installed is on the outside wall and can see 4 other APs all blasting away on channel 6.
Wednesday - last edited Wednesday
I just had a quick walk around, using wifi Analyzer, on the AP the laptops are connected to there is no other overlapping AP. To verify I held the analyzer on the location where the laptops are. The only other AP's that were in range were very low signal and on either channel 1 or 6.
Edit :- I've just done some more testing with Acrylic Wi-Fi Home, its picking up lots of random home AP's around albeit at a very low signal. Could that be causing my problems?
IMHO its the utterly absymal Wireless N 7260 adapter. Every laptop I've ever seen regardless of manufacturer with that adapter has had issues. If you google it you'll find literally thousands of results and dozens of threads in support forums (like HP, Lenovo, Asus & others) moaning about the stability/speed of them.
IIRC there was another thread on these forums relating to 7260 adapters although that might be the AC 7260, can't remember but if you have a search you might find it.
The AC 7260 works very well I upgraded my acer laptop from a Broadcom N to it and the only complaint I have with it is Intel will not support 802.11r/v/k on it.
The only alternative card I can find of the same form factor is an AC 7260 rather than the N version.
Any half mini pci-e card should work. I personally prefer the BCM94532HMB. Just google half mini pci-e wireless.