Yes, this is exactly the sort of thing I was envisioning and trying to describe. David Lang On Tue, 19 Apr 2016, Aaron Wood wrote: > What about a strip-chart with multiple lanes for every device. Then use > either a line graph or a spectrograph (color of band) style marking to show > data rate used at that time. If the main goal is fairness and airtime, > then the eye can visually compute that based on how evenly spread out the > slices of usage are, and can identify problematic places based on color of > the band (or height of the line, if using a spark-lines instead of patches > of color. > > I've done this in the past to visualize offline devices in a mesh network, > and the result of that was _very_ useful for showing how losing one node > takes out the ones that needed to route through it, also useful for showing > when failures were time-correlated or not. > > Multicast messages could then be shown as grey bands across the whole set > of spectrum, and inter-packet as just whitespace (or maybe thin black > lines). > > If you were more interested in showing sent vs. received, then you could do > two stripes per station, one for tx and one for rx. > > For higher encoding rates, the preamble could be shown in the 1Mbps/11Mbps > color, and then the rest of the payload in a different color for the MCS > used. That will show efficient aggregation vs. inefficient aggregation. > > Hmm... I kinda want to sketch this up using matplotlib. I've used a > couple pcap libraries (like scapy) with python. They're not fast, though > (scapy does about 2500pps in reading/parsing pcap files on my computer). > That might be better if it was told to only parse the radio-tap header and > ignore the rest of the packet. > > -Aaron > > On Mon, Apr 18, 2016 at 6:42 PM, David Collier-Brown > wrote: > >> On 18/04/16 07:03 PM, David Collier-Brown wrote: >> >> I haven't internalized this yet, but my instantaneous reaction is: >> >> - a radar screen is something people have been educated to >> understand, so that's cool, and >> >> Rat's, it all went on one line. This is more like what I meant >> >> >> - over time, plotting the time taken for against the load >> in s is what capacity planners expect to see: "_/" >> >> >> --dave >> >> On 18/04/16 06:48 PM, David Lang wrote: >> >> On Mon, 18 Apr 2016, Dave Taht wrote: >> >> I have been sitting here looking at wifi air packet captures off and >> on for years now, trying to come up with a representation, over time, >> of what the actual airtime usage (and one day, fairness) would look >> like. Believe me, looking at the captures is no fun, and (for example) >> wireshark tends to misinterpret unreceived retries at different rates >> inside a txop as tcp retries (which, while educational, makes it hard >> to see actual retries)... >> >> Finally today, I found a conceptual model that "fits" - and it's kind >> of my hope that something already out there does this from packet >> captures. (?) Certainly there are lots of great pie chart tools out >> there... >> >> Basically you start with a pie chart representing a fixed amount of >> time - say, 128ms. Then for each device transmitting you assign a >> slice of the pie for the amount of airtime used. Then, you can show >> the amount of data transmitted in that piece of the pie by increasing >> the volume plotted for that slice of the pie. And you sweep around >> continually (like a radar scanning or a timepiece's pointer) to show >> progress over time, and you show multicast and other traffic as eating >> the whole pie for however long it lasts. >> >> conceptually it looks a bit like this: >> >> http://blog.cerowrt.org/images/fairness.png (I borrowed this graph >> from >> http://www.webdesignerdepot.com/2013/11/easily-create-stunning-animated-charts-with-chart-js/ >> ) >> >> Another way to do it would be to have the pie represent all the >> stations on the network, and to have the "sweep hand" jump between >> them... >> >> >> does it really matter how much data is passed during the timeslice as >> opposed to just how much airtime is used? (and there will be a large chunk >> of airtime unused for various reasons, much of which you will not be able >> to attribute to any one station, and if you do get full transmit data from >> each station, you can end up with >100% airtime use attempted) >> >> I would be looking at a stacked area graph to show changes over time (a >> particular source will come and go over time) >> >> I would either do two graphs, one showing data successfully transmitted, >> the other showing airtime used (keeping colors/order matching between the >> two graphs), or if you have few enough stations, one graph with good lines >> between the stations and have the color represent the % of theoretical peak >> data transmission to show the relative efficiency of the different >> stations. >> >> >> While the radar sweep updating of a pie graph is a neat graphic, it >> doesn't really let you see what's happening over time. >> >> David Lang >> >> _______________________________________________ >> Bloat mailing list >> Bloat@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/bloat >> >> >> >> -- >> David Collier-Brown, | Always do right. This will gratify >> System Programmer and Author | some people and astonish the restdavecb@spamcop.net | -- Mark Twain >> >> >> >> -- >> David Collier-Brown, | Always do right. This will gratify >> System Programmer and Author | some people and astonish the restdavecb@spamcop.net | -- Mark Twain >> >> >> _______________________________________________ >> Bloat mailing list >> Bloat@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/bloat >> >> >