Indoor Wi-Fi Roaming with OpenWRT

54 points - last Tuesday at 4:41 PM

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goodburb today at 3:14 PM
You can stick to 802.11r only by lowering the transmission power and have all the APs on the same channel, in my tests it ended up switching much faster than K/V. (~75ms)

On iOS, equal channel with correct ESS will switch liberally. On Android 14+ with Broadcom chip it will start conservative, then switch liberally after the first poor signal switch-over event, up until disconnection.

Android (Pixel/Moto) will never switch (even with K/V) on large network activity, only VoIP/video call. It depends on vendor implementation. I use "dp.logcatapp" log reader while roaming, "ModemStats" shows the score/load and is used on most vanilla builds.

Samsung is known to push protocol support early: 802.11r in 2013, 802.11w 2015, some models do not use Android's default connectivity manager.

To add, WPA3 with 802.11r is known to have issues on Apple hardware before 2021 on all iOS versions, many Android devices, especially smart TVs don't support it, will not connect or are unreliable (protected beacon frame), can be searched in buried report results at OpenWrt forum mega threads and Ubiquity. WPA2+FT and forced MFP with a long password is a safe alternative.

802.11K/V is more suitable for campus and load balancing, tuning it based on RSSI and station metrics is very difficult, enterprise hardware rely on network traffic and air time.

lxgr today at 3:55 PM
> The obvious advice for roaming is “use one SSID everywhere”, and that is often correct if you’re running Wi-Fi in an office, a public venue, or generally somewhere where you don’t have (or care about) legacy devices.

What difference does the presence of legacy devices make? Is the intent to isolate them from modern devices from a network perspective? Then create a separate SSID on both 2.4 and 5 GHz for modern devices.

I can't think of any legitimate reason for split SSIDs anymore. Linux clients used to be pretty bad at preferring 5 over 2.4 GHz if RSSIs were both excellent but 2.4 was slightly better, but I haven't seen that in years.

ghrl today at 3:19 PM
I don't quite understand the benefit of the setup. If there are legacy IoT devices that need unique named 2.4G network, just broadcast another SSID for them. So each router broadcasts main 5G (common name, fast roam etc), main 2.4G (same as above) and legacy IoT 2.4G (with a different name for each AP, and possibly worse encryption and maybe even TKIP). That wouldn't hold back the network for legacy devices.
wwweeee today at 4:02 PM
Using only 6ghz, turned off 2.4 & 5. Problem solved.
Jabdoa2 today at 3:36 PM
You can also "just" set the 802.11k entries manually. Add 802.11r and you should be mostly good. Usteer makes it slightly better by moving clients to the best AP when they stay stationary for longer whiles.
jonhohle today at 2:59 PM
I need to spend some time on it but I purchased two Omada APs to pair with my OpenWRT router thinking roaming would just work with mostly Apple devices. That didn’t happen. I’m hoping some of this article applies and I can improve the situation a bit.
thenthenthen today at 3:38 PM
Cool! I dont need this anymore since im broke and moved to a 1 room apt. but yeah the ‘set the same ssid’ “trick” def. is not enough and often achieves the opposite effect.
ruptwelve today at 3:19 PM
When I move from Europe to the US I realized that roaming is not as prevalent here as it is back home. The (mostly) wooden houses enable me to just use one really powerful AP for most of my needs.
jauntywundrkind today at 3:10 PM
I'd used DAWN for band steering/roaming at my last place, which worked ok. uSteer is a little newer & is an official openwrt project. https://github.com/berlin-open-wireless-lab/DAWN https://openwrt.org/docs/guide-user/network/wifi/dawn DAWN has a wild amount of knobs to tune, which aren't super well described. I haven't been running it since a single AP covers my current place very well. But it would be interesting to go evaluate DAWN & it's config with an LLM, to dice in & see more. uSteer too.

Great write up, good information to share. This really is such an important next step for many people's wifi and it's documentation is pretty so-so.