As far as I can judge, a key element in a correctly setup controlled Wifi network is using the right channels for each AP to avoid interference.
Back in ROS6 Capsman I almost always used RegEx based provisioned channels based on /system identity, because I was never impressed by the AC radios ability to pick a clear channel.
With ROS7 and the wifi-qcom package this appears to be better, but there are some pitfalls.
I have tried a few installations with forced channels via RegEx also here, but I tend to achieve poor performance. And with a static channel, I don’t account for external sources like neighbor networks that I don’t control.
OTOH, leaving it all to the radios and setting reselect-time to 03:00:00..04:00:00 each AP re-evaluates its channels on a different time and it looks like they are distributed rather well.
But after a power outage they all start up and scan simultaneously, and the 5GHz radios tend to all pick 5500.
They will then sit that way until the following night before re-evaluating, causing massive interference, lag and disconnects. And angry users.
Of course, using the property reselect-interval the APs might do their magic earlier, but then the client connections will be broken.
So what do you guys use to handle this?
Some script running after startup?
And are you using connect-priority and/or access lists to improve handover?
BTW why is connect-priority located under sequrity?
Good questions, have run into these as well (though my networks might be smaller than yours).
Power outage can be prevented by using UPS (assuming you power the accesspoints through a PoE capable switch).
Unfortunately, the startup is not helping in regards to selecting proper channels. I use reselect-interval to perform background scanning, this indeed interrupts the radio if a DFS channel is selected, but my clients just roam to the best alternative (being 2.4GHz radio).
Best roaming experience for me is by using both FT (for capable clients) and setting connect-priority=0/1 (for non FT capable devices).
Using access-lists in regards to handover should be avoided as clients handles the disconnects by the AP in a different way.
Last tip, set bandwidth to 20MHz on 2.4GHz and 40MHz on 5GHz radio to limit interference.
Hope this helps. Perhaps you can share a bit more about the environment you are referring to?
I have been running into this issue many times, this time it is about an enterprise with coverage both inside offices, in 2 workshops, in a warehouse, and outdoors.
Especially I want to avoid unintended interference between APs in offices and the AP in the warehouse one story down.
Yes I know I can use UPS, but sometimes the APs will be restarted anyway, be it during ROS/FW upgrade or simply by some fella disconnecting LAN (PoE) cables.
Of course I could use reselect-interval, maybe country=superchannel will avoid DFS-scanning?
Can you elaborate on how you use FT and connect-priority, as this is unfamilar to me?
Examples?
The biggest (relatively) installation I have: a warehouse with 16 APs (mix of cAP AX and AX3).
I took floor plans, marked the locations for all APs and assigned channels manually so there are no overlaps (each cell has at least 1 cell between another one using the same channel).
Both 2.4 (using 1/6/11 scheme) and 5GHz (mostly only lower range since the used scanners can not use UNI-II, let be UNI-III). And then I provisioned those using MAC address from radio.
I will admit I am lucky there is not too much interference from outside there (and all printers are under my control, NONE broadcast wifi).
As suggested, 20Mhz for 2.4Ghz channels, max 40MHz for 5Ghz (in warehouse I also use 20Mhz since mostly Symbol scanners are being used there, very low bandwidth).
I think the 2,4ghz is OK, but I would maybe want to add another 2,4ghz AX and I’m not sure I want to do something more with the 5ghz? Most units seem to prefer the 2,4 ghz, which is a bit unexpected.
When using automagic channel selection, please consider using the reselect-interval as well. Without, the channel is only set once (while during starting) and could cause having all radios (per band) use the same frequency.
There are a couple of tweaks you can play with having clients prefer 5GHz over 2.4GHz:
2g-probe-delay (being part of the steering properties)
lowering Tx Power (part of configuration) on the 2.4GHz radio
There are more, these are in my opinion the most elegant.
But in the end, clients decide for themselves.
I do not mind use “fixed” channels for the 5ghz as well I just lack knowledge on what those should be. There seems to be more concensus on what channels to use on the 2,4ghz band but not as much for the 5ghz?
Indeed there is less consensus...DFS channels or not, U-NII-3/4 or not?
In the end it depends...depends on number of radios in your network, wireless networks in your environment, external factors (like radar) that define what channels to use.
Currently, anything can happen. Not really optimized in my opinion.
Please consider these settings:
Unlike @erlinden, my APs have wpa-2 and wpa-3 combined. Then it's up to client capabilities and preference to use one of these two. Most clients which support WPA-3 will prefer using it if offered.
There are rumours that FT roaming doesn't work well with WPA-3 ... but my own experience doesn't support that (I see WPA-3 clients which display ft-wpa3-psk in registration table and AFAIK that indicates that FT was used when station moved from one AP to another the last time).
Ok, thank you, the idea right now is to just have one AP, I had 2 CAP AC at the house before, but the idea is that I will most likely be OK with just one CAP AX, many more heavy traffic clients, gaming PC and so on will be on ethernet and mainly the “smart home devices” will be on wifi, that require it. So I should not need roaming of the other fancy stuff.
Roaming is very useful in between radios. I.e. when signal of the 5GHz radio is too low, clients can roam to the 2.4GHz radio. But it depends on your requirements, does it have to be seamless?
You stated "I have the same question", but your question is actually completely different.
Hope it is answered anyway.
I’m sorry you are correct, my question as in relations to selecting the correct channels for 5ghz, but I understand that my use case differs from the one by the thread starter.
I never understood that roaming could be between radios, allways just assumed it was between “units”, but it makes sense and I guess if possible why would I not want “seamless” roaming.
Thank you all for your support I will try out the new config when I get back home.
In AX drivers, it is not possible to disable compatibility mode with the b standard; all service broadcasting is on the b standard, hence the 22 MHz bandwidth and the use of only triples 1-6-11 or 1-7-13 with a distance between channels of 25 or 30 MHz. The four channels 1-5-9-13 cannot be used because the distance between channels is 20 MHz.
There are no specific frequencys for the 2,4ghz specified, you removed the ones I had, any specific reason for this?
The 2ghz is not setup for AX but I guess in by allow in provisning setting “supported-bands=2ghz-n” it will also allow the older units that only support N?
I added the three freqencys from my first config but otherwise what you sugggested, looks much better now:
The frequencies is part of the tweaking, adding those like you did is just perfect.
By adding the 2ghz-n to the provisioning rule, also older devices are supported. Actually, you can leave the 2ghz-ax, as that is already covered by the 2ghz-n setting. The CAP will still use highest possible speed, it is just used to identify the radios capabilities.
Glad it improved, still I would expect higher rates as you support 80MHz bandwidth on the 5GHz radio. What Signal do the clients have?
I’ll check the the signal when I get home, but I do not expect much at this stage, we are waiting to move in to our house, untill then everything is just in an “as is state”, so the AP is installed this way:
