Posted: Mon Nov 30, 2020 13:18 Post subject: R9000 and 2.4GHz Dynamic (20/40 MHz) Mode
I've been running r43397 on my R9000 since June and it's been quite reliable. I'm occasionally tempted to upgrade, but, well, I always manage to talk myself out of it.
Over the weekend, I started to see extremely poor performance on the 2.4GHz network, which also hosts a VAP for my IOT hardware. I narrowed it down to an older iPad I have in the kitchen that's used exclusively for monitoring a webcam that covers our driveway. If I exited the webcam app on the iPad, performance would return to normal. Launched it, and connectivity would again become spotty.
I thought there might be something I could do on the router that might help; I'd had the 2.4GHz network configured for Full (20 MHz) since installation of r43397, and decided to try Dynamic. It seemed to help, but only marginally. Upgrading the webcam app on the iPad made a bigger difference and things seemed to return to normal.
That is, until approximately 4am this morning when the R9000 hung completely ... no wifi, and all lights were lit solid (normally some are blinking with activity). I rebooted and the router returned to normal operation and has been fine for the last 90 minutes.
Prior to setting Dynamic mode I'd made no configuration changes for months. So this hang event seems a bit too coincidental.
Joined: 21 Jan 2017 Posts: 1783 Location: Illinois Moderator
Posted: Mon Nov 30, 2020 14:49 Post subject:
Dynamic mode has always been spotty and it's recommended to run straight HT20 mode or VHT40, but not the dynamic version. The Ipad will never use VHT40 and neither will the webcam... their firmware is hard baked to "play nice" and will never use VHT40.
Also to note is that you're running an older build now and there have been a bunch of changes to the wifi radio drivers and firmware on the R9000.
I would recommend updating to 44715 for the moment and then re-examine my recommended qca wifi settings to make a few tweaks... The newer builds have had a lot of changes lately and have been spotty and are not recommended by me for the R9000/R7800. 44715 is a solid build.
RTS/CTS threshold should be turned on and used, set it to 784. Also new beacon intervals are being recommended...see my signature. _________________ FORUM RULES
Thank you, @msoengineer. I've been using your QCA settings up through the installation of r43397 but will make sure the upgrade to r44715 gets your updated settings.
The enabling of Dynamic mode wasn't so much to improve the performance of the iPad but the other devices on the 2.4GHz network. Aside from the old iPad there's a 4K TV, a bunch of Echos, smart bulbs/switches/plugs, thermostats, phones, and a couple of kitchen appliances. When the iPad was acting up, the TV became pretty much useless for streaming and all of the smart devices were disconnecting/reconnecting constantly.
All of the devices currently connected to the 2.4GHz network are showing as HT20SGI, VHT20SGI and LEGACY; does that mean that HT40 isn't being used at all?
Joined: 21 Jan 2017 Posts: 1783 Location: Illinois Moderator
Posted: Mon Nov 30, 2020 16:46 Post subject:
Outside intel wifi cards, which you can instruct to use VHT40, everything else will always use HT20; which is why I say don't even bother with VHT40 mode on the router for 2.4ghz in the wifi wiki.
I have several intel clients on my network so I end up using VHT40, but no IoT, phone, or tablet will connect at VHT40 rates...so... what you are seeing is normal and intentional to adhere to 802.11 neighbor friendly rules.
As far as the dropping issues...try the RTS/CTS threshold changes and beacon interval...
BI=300(5ghz) and 400(2.4ghz) seems to have solved a lot of my weird drop issues on nearly all clients...
also, make sure to use airtime fairness on the router so a shit 2.4ghz client can't dominate the network traffic and eat all the bandwidth for the other clients...sounds like your issue...(although svn ticket is unrelated, BS's comment here applies to airtime fairness demonstrating the need for the option to be turned on) _________________ FORUM RULES
Gotcha. The only Intel wifi cards I have are in 3 laptops, and they're all connected via the 5GHz network.
I've also reviewed bandwidth this morning on the 2.4GHz network and the minor boost in performance I saw after I enabled Dynamic mode seems to have been ... transient in nature.
