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a couple of weeks ago we've had a company install four access points and perform the initial setup. We asked to have three different WiFis, one for our primary work devices, one for our personal devices and a third one for guests. Three of those access points are on one side of the building and the fourth is on the other side where we have a single meeting room. They installed the APs and did the initial config, then gave us the admin credentials for the config UI.

For the past two weeks we've had individual complaints of "slow WiFi" or "Confluence not responding" until we had people run ping 8.8.8.8 throughout the day. We quickly discovered how the observed problems coincides with their machines suffering from packet loss, e.g.

87 packets transmitted, 48 packets received, 44.8% packet loss
round-trip min/avg/max/stddev = 19.603/93.004/459.626/84.396 ms

Please note that at one point I was sitting right next to an affected colleague while my connection was fine. At that time were connected via different channels, so we had a look at the output of /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -s:

            SSID BSSID             RSSI CHANNEL HT CC SECURITY (auth/unicast/group)
       NeighborD 74:67:xx:xx:fe:50 -83  13      Y  DE WPA2(PSK,FT-PSK/AES/AES) 
 WiFi 3 (Guests) dc:08:xx:xx:2b:eb -64  60      Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 1 dc:08:xx:xx:2b:ea -63  60      Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 2 dc:08:xx:xx:2b:e9 -62  60      Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
 WiFi 3 (Guests) dc:08:xx:xx:69:8b -47  60      Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 2 dc:08:xx:xx:69:8a -47  60      Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 1 dc:08:xx:xx:69:89 -47  60      Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
       NeighborD 74:67:xx:xx:22:00 -91  136,-1  Y  DE WPA2(PSK,FT-PSK/AES/AES) 
       NeighborA 00:1a:xx:xx:2c:9b -89  132,+1  Y  DE NONE
       NeighborB 5c:49:xx:xx:8b:0d -73  124     Y  DE WPA2(PSK/AES/AES) 
       NeighborA 00:1a:xx:xx:2c:93 -72  11      Y  DE NONE
          WiFi 1 dc:08:xx:xx:2b:e2 -56  11      Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
 WiFi 3 (Guests) dc:08:xx:xx:2b:e3 -57  11      Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 2 dc:08:xx:xx:2b:e1 -57  11      Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 1 dc:08:xx:xx:73:c2 -80  6       Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
 WiFi 3 (Guests) dc:08:xx:xx:69:83 -50  6       Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 2 dc:08:xx:xx:69:82 -50  6       Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 1 dc:08:xx:xx:69:81 -50  6       Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
       NeighborC cc:ce:xx:xx:d8:48 -81  1       Y  DE WPA2(PSK/AES/AES) 
  NeighborC Gast ce:ce:xx:xx:d8:49 -82  36      Y  DE WPA2(PSK/AES/AES) 
       NeighborC c8:0e:xx:xx:c4:1b -77  36      Y  DE WPA2(PSK/AES/AES) 
       NeighborC cc:ce:xx:xx:d8:49 -82  36      Y  DE WPA2(PSK/AES/AES) 
  NeighborC Gast ca:0e:xx:xx:c4:1b -77  36      Y  DE WPA2(PSK/AES/AES) 
 WiFi 3 (Guests) dc:08:xx:xx:2b:f3 -67  149     Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 1 dc:08:xx:xx:2b:f2 -67  149     Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 2 dc:08:xx:xx:2b:f1 -66  149     Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
 WiFi 3 (Guests) dc:08:xx:xx:69:93 -47  100     Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 2 dc:08:xx:xx:69:92 -47  100     Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 
          WiFi 1 dc:08:xx:xx:69:91 -47  100     Y  US WPA(PSK/AES,TKIP/TKIP) WPA2(PSK,FT-PSK/AES,TKIP/TKIP) 

This tells me that two APs are using channel 60 and might therefor create interference among the different APs. Unfortunately we've also received complaints for channel 100 so I'm guessing WiFi 1, WiFi 2 and WiFi 3 also shouldn't share channels... Is that correct? Any input is welcome!

2
  • Are your 3 "Wifi's" (actually WLANs) available on each of the four access points?
    – Ron Trunk
    Nov 20, 2019 at 1:45
  • Yes, they are centrally configured with the master AP (one of the four) and then all four of them use the same WLAN SSID and password.
    – oschlueter
    Nov 22, 2019 at 8:04

1 Answer 1

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Always setup access points in a way so the channels are as much apart as they can be. If two access points are working on the same channel the client with worse antenna (like a cell phone or just different laptop) might want to try to switch over from one AP to another and back again which will cause significant packet loss or even disconnections for a brief period of time.

From you log I see that you have two AP's on channel 60 which is not good. Switch any of them to a different channel - ideally that's not being used by other AP's (not just yours). For example you can use channel 116.

Another thing is channel width - do you use 20,40,80 MHz wide channels ? Have a look at 5 GHz channel table here to understand better how to they work.

And here's even more to help you. These are the best practices for setting up a good performing wi-fi network.

Depending on hardware you use you can do a spectrum scan to tell you what is the least used channel. Mikrotik, Ubiquiti and some other devices have this feature ready for use.

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