Re: [Make-wifi-fast] mesh deployment with ath9k driver changes

[Pete Heist <pete@eventide.io>]

Hi, thanks for the tips…most everything seems to be already set similarly in Open Mesh’s config except:

- the disabling of lower rates- interesting idea and maybe the most consequential, I’ll see if I can do this in one of OM’s custom.sh scripts, otherwise it’s easy to do in plain OpenWrt
- client isolation isn’t supported when bridging to a VLAN, which I’m doing at the moment

It’s taking some convincing, but I have a rough plan to dig a minimal trench for a new cabled gateway to split cabins 12 and 20, which is the primary issue. If ground isn’t broken soon, it might be me at the shovel. :) Most definitely I’ll report back as I want to do some more testing on the ath9k changes, once this physical issue is taken care of...

> On May 19, 2018, at 6:03 PM, bkil <bkil.hu+Aq@gmail.com> wrote:
> 
> In reply to this thread:
> https://lists.bufferbloat.net/pipermail/make-wifi-fast/2018-April/001787.html
> 
> Sorry for the late response, although I can see from yesterday's
> SmokePing plots that the issue still prevails.
> 
> 1.
> You should definitely not allow rates as low as 1Mb/s considering:
> * plots of signal vs. rate,
> * topology of closely packed cabins;
> * mostly static, noise-free camp ground.
> 
> Almost all of your clients were able to link with >20Mb/s even at
> 70-80dBm. Those below were probably just idling. I'd limit the network
> to 802.11g/n-only, and would even consider disabling all rates below
> 12Mb/s.
> 
> This should help both in working around imperfect schedulers and
> clients roaming.
> 
> You could double check the coverage afterwards with a simple site
> survey. You may also test whether disassoc_low_ack makes things more
> stable around the edge.
> 
> Despite the recently introduced air fairness patches, most other
> points are still valid from these earlier articles due to pathological
> schedulers:
> http://divdyn.com/disable-lower-legacy-data-rates/
> https://blogs.cisco.com/wireless/wi-fi-taxes-digging-into-the-802-11b-penalty
> https://www.networkworld.com/article/2230601/cisco-subnet/dropping-legacy-802-11-support-from-your-infrastructure--part-2-.html
> 
> Disabling 802.11/b modulation also brings the added benefit of
> occupying less bandwidth (16.5-20 OFDM vs. 22 Barker/CCK), enabling
> the previously mentioned channel spacing of 1-5-9-13.
> 
> https://wifinigel.blogspot.hu/2013/02/adjacent-channel-interference.html
> 
> 2.
> Enable client isolation to mitigate broadcast storms.
> 
> 3.
> If you still couldn't split the two cells that work on the same
> channel, at least try to reduce their TX power to reduce their range
> of interference. This may or may not improve things overall due to
> hidden nodes, though.
> 
> We'd definitely love to hear from you whether any of these worked or
> made things worse. Happy camping!