Re: [lime] Results on distance setting influence on performa…

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Author: SAn
Date:  
To: LibreMesh.org project mailing list
Subject: Re: [lime] Results on distance setting influence on performances
Thanks for sharing!

What is your opinion on the data? :)

The environment is very low noise/interference or not?
I think that the ratio of tx retries / tx packets give also some information as if the retries are "high" then the impact of the idle time due to waiting for the ack (that will not come, or is lost) to start the retry greatly impacts latency (and also throughtput). As latency is also important maybe using some of the tools of the bufferbloat project can also be interesting https://www.bufferbloat.net/projects/bloat/wiki/

Best!
SAn


On August 15, 2023 11:26:21 AM GMT-03:00, Ilario via LibreMesh <libremesh@???> wrote:
>Dear all,
>with Gothos (a.k.a. Samlo, our GSoC student for this year), we performed some measurement on the influence of a too-large distance setting on two mesh (iee802.11s on 5 GHz) wifi links, one of 1200 m and another of 2100 m. Actually, the real-world measurements have been taken by Gothos on some real nodes of this community: https://antennine.noblogs.org/
>
>We checked what happens, on both links, when changing the distance setting between 2100 m, 5 km and 10 km, without changing anything else, just a parameter in OpenWrt. And measuring the real bandwidth with bidirectional iperf3.
>
>This has been done for deciding over this topic:
>https://github.com/libremesh/lime-packages/issues/201
>(which is a good default value for the distance setting)
>and we could (should) implement the output of this discussion (i.e. a better default value) in the upcoming releases.
>
>This email is for sharing with you the results and the code, in case anyone is willing to measure this on their routers, or to perform more optimizations of other parameters!
>In a following email, Gothos will tell us more about the physical setup at the testing site, router models, signal level etc.
>Also, anyone is welcome to share their opinion on the data!
>
>Here you are:
>https://github.com/ilario/wifi-distance-setting-exploration
>
>The script in Python, I wrote for allowing anyone to plot data taken modifying any parameter, not only the distance one. But the data has to follow the format generated by the bash commands reported in the README file that you can find in the repository.
>Also these commands will have to be slightly adapted for exploring other parameters, obviously.
>
>One thing I want to say already: it is possible that at minute 0 and minute 5 of the measurements (Gothos, is this right?) there is an effect of a cron job that was running on the nodes performing a wifi scan every 5 minutes (equivalent to job of the wifi-unstuck-wa package that you can find in the lime-packages repository).
>
>Ciao!
>Ilario & Gothos
>
>
>