802.11r - connection dropouts during handover

[shaarkys]

Hi,
sharing my topology for better understanding - basically two AP Ubiquiti connected into EdgeRouter via LAN cable, having same SSID and enabled 802.11r. Using DAWN - but no difference if it's enabled or disabled.

I have following problems - when I migrate from one AP to 2nd, seems that there is always 3-6 sec dropouts (eg. when listening to online radio), while having conference (Webex) the dropout is even longer (20 sec).

When diagnosing this with Signal mapper (WifiMan Android app), seems that handover is ok but I don't know what can be done to shorten that dropout - according to my research it shall be around 100ms and not 6000ms...

Logs confirming 802.11r works :

Wed Mar  9 09:47:23 2022 daemon.notice hostapd: wlan0: AP-STA-DISCONNECTED f4:02:28:7a:ad:a8
Wed Mar  9 09:47:23 2022 daemon.err hostapd: nl80211: kernel reports: key addition failed
Wed Mar  9 09:47:23 2022 daemon.debug hostapd: wlan0: STA f4:02:28:7a:ad:a8 IEEE 802.11: binding station to interface 'wlan0'
Wed Mar  9 09:47:23 2022 daemon.debug hostapd: wlan0: STA f4:02:28:7a:ad:a8 IEEE 802.11: authentication OK (FT)
Wed Mar  9 09:47:23 2022 daemon.debug hostapd: wlan0: STA f4:02:28:7a:ad:a8 MLME: MLME-AUTHENTICATE.indication(f4:02:28:7a:ad:a8, FT)
Wed Mar  9 09:47:23 2022 daemon.debug hostapd: wlan0: STA f4:02:28:7a:ad:a8 IEEE 802.11: association OK (aid 2)
Wed Mar  9 09:47:23 2022 daemon.info hostapd: wlan0: STA f4:02:28:7a:ad:a8 IEEE 802.11: associated (aid 2)
Wed Mar  9 09:47:23 2022 daemon.notice hostapd: wlan0: AP-STA-CONNECTED f4:02:28:7a:ad:a8
Wed Mar  9 09:47:23 2022 daemon.debug hostapd: wlan0: STA f4:02:28:7a:ad:a8 MLME: MLME-REASSOCIATE.indication(f4:02:28:7a:ad:a8)
Wed Mar  9 09:47:23 2022 daemon.debug hostapd: wlan0: STA f4:02:28:7a:ad:a8 IEEE 802.11: binding station to interface 'wlan0'
Wed Mar  9 09:47:23 2022 daemon.debug hostapd: wlan0: STA f4:02:28:7a:ad:a8 WPA: event 6 notification
Wed Mar  9 09:47:23 2022 daemon.debug hostapd: wlan0: STA f4:02:28:7a:ad:a8 WPA: FT authentication already completed - do not start 4-way handshake

I can share the configs but wifi configs, even default, behaves the same. I'm having suspicious about some "transition timeout / keepalive" TCP/UDP parameter but can't find any.

Not using any VLAN, having disabled firewalls...

Any suggestions please, someone experienced the same ?

Thank you.

[shaarkys]

So I thought it will be problem with wireless APs but seems it was not the case - I rebuild and reset my build config for Edgerouter X and seems to be working fine now. Interesting that I was using the same config for such a long time and without any other issues.

In my case that problem was caused by Routing/NAT offloading on the main router Ubiquiti EdgeRouter X with two APs - Ubiquiti UniFi AC Lite and Ubiquiti UniFi AC Pro - disabling both option on EdgeRouter ensures that Fast Roaming really works without ANY interruptions .

Devices roaming fine but have glitch - 5s after roaming

Devices roams fine without any glitch after roaming...