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

Toke Høiland-Jørgensen toke at toke.dk
Tue Apr 24 07:54:31 EDT 2018

Pete Heist <pete at eventide.io> writes:

> I have a 7 node (3 of which are repeaters) mesh deployed at a campground using Open Mesh’s 6.4 beta (with LEDE and the ath9k changes). I set up an internal SmokePing instance with each AP as a target, and the first guests of the season are arriving (school kids, the best testers). The setup for our three repeaters is:
> Cabin 12: 110 meters and RSSI -69 to gateway, NLOS through a few leaves
> Cabin 20: 65 meters and RSSI -66 to gateway, LOS but maybe some fresnel zone intrusion from leaves or branches
> Cabin 28: 50 meters and RSSI -51 to gateway, clear LOS
> Attached are some PDFs of the current SmokePing results. The school
> arrived Monday morning and are mostly clustered around cabins 12 and
> 20, with a few around cabin 28, can you tell? :) Mean ping time for
> cabin 12 is around 200 ms during “active use”, with outliers above 1
> second, which is higher than expected. I don’t have data collected on
> how many active users that is and what they’re doing, but there could
> be 40-50 students around the cabin 12 AP, with however many active "as
> is typical for kids”.

Hmm, yeah, 200ms seems quite high. Are there excessive collisions and
retransmissions? Is the uplink on the same frequency as the clients?

> Overall it would be nice to know, in a typical real-world setup, how
> much is WiFi latency is due to bufferbloat, and how much to the
> physical layer?

On ath9k bufferbloat should be more than 10-20ms or so.

> Lastly, is there any interest in access to SmokePing results, or other
> diagnostics? Things are bound to get interesting as the season
> progresses…

Sure, feel free to keep us updated! :)


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