Mail mail provider unhelpfully labelled my post as SPAM, and apparently all receivers rejected to receive my "SPAM" Hence I try forwarding a slightly edited version of my response below, hoping not to trigger GMX's SPAM detection again.
> Begin forwarded message: > > From: Sebastian Moeller <moell...@gmx.de> > Subject: Re: [Make-wifi-fast] [Rpm] make-wifi-fast 2016 & crusader > Date: December 8, 2022 at 11:15:12 GMT+1 > To: rjmcmahon <rjmcma...@rjmcmahon.com> > Cc: rjmcmahon via Make-wifi-fast <make-wifi-f...@lists.bufferbloat.net>, Dave > Täht <dave.t...@gmail.com>, Rpm <r...@lists.bufferbloat.net>, libreqos > <libreqos@lists.bufferbloat.net>, Dave Taht via Starlink > <starl...@lists.bufferbloat.net>, bloat <bl...@lists.bufferbloat.net> > > Hi Bob, > > thanks for the detailed response. > > >> On Dec 7, 2022, at 20:28, rjmcmahon <rjmcma...@rjmcmahon.com> wrote: >> >> Hi Sebastian, >> >> Per Aristotle: "That which is common to the greatest number gets the least >> amount of care. Men pay most attention to what is their own: they care less >> for what is common." >> >> I think a challenge for many of us providing open source tooling is the lack >> of resource support to supply goods for all. Both the iperf 2 and iperf 3 >> teams are under-resourced so we try not to duplicate each other too much >> except for where that duplication adds value (e.g. having two independently >> written socket measurement tools.) The iperf 3 team has provided public >> servers, I think at their costs. > > [SM] I should probably clarify my position, I was not trying to argue > that you (or your employer) should operate public iperf2 servers, but that > the availability of such servers probably is what made iperf3 the most > popular of the iperf2/iperf3/netperf triple. I did not realize that the > iperf3 team operates some of the public servers, as I have already seen ISPs > (see e.g. hxxps://speedtest.wtnet.de) that offer iperf3 as mean for their > existing users to run speedtest via iperf3. So my argument should gone more > along the lines of, "to make iperf2 as popular as it deserves to be some > publicity and available servers will help a lot". And actually having servers > operated by other parties than the toll maker is an added "vote of > confidence". > > >> I've been holding off on iperf 2 public servers until I found an additional >> value add and a way to pay for them. > > [SM] Understood, and I formulated inartfully, implying you should host > iperf2 servers; that was not my intent. > >> Much of the iperf 2 work has been around one way delay (OWD) or latency. >> Doing this well requires GPS clock sync on both the data center servers and >> the end host devices. I checked into this a few years ago and found that >> this level of clock sync wasn't available via rented servers (e.g. linode or >> Hurricane Electric) so I put on hold any further investigation of public >> servers for iperf 2 as being redundant with iperf 3. Those that need true >> e2e latency (vs RTTs) have to build their own so-to-speak. > > [SM] Yepp, except for congestion detection all that is really required > is sufficiently stable clocks, as the delay differences between idle and > loaded tests are quite informative and offering OWDs allows to pinpoint the > direction of congestion. > >> I know of two nonprofit measurement labs being mlabs and ripe (there may be >> more) that could take an interest but neither has: >> >> hxxps://www.ripe.net/ >> hxxps://www.measurementlab.net/ > > [SM] I think ripe especially their ATLAS network is somewhat > "sensitive" about throughput tests, as quite some nodes likely are operated > by enthusiasts in their leaf networks that are not well suited as generic > speedtest servers... (however that would allow great studies of achievable > throughput comparing different ASs). > >> There could be a market opportunity for somebody to build a measurement >> system in the cloud that supported any generic sensors and could signal >> anomalies. Then one could connect iperf 2 public servers to that as an >> offering. >> >> Note: Some GPS atomic clock options for RPi: >> hxxps://store.uputronics.com/index.php?route=product/product&product_id=81 >> hxxps://store.timebeat.app/products/gnss-raspberry-pi-cm4-module?variant=41934772764843 > > [SM] I followed your lead several moths ago, and have an > GPS-disciplined NTP server in my homenetwork already, so I am prepared for > true OWD measurements ;) > > >> Also needed is the latest iperf 2 on an openwrt router. > > [SM] That will work well for the low throughput test, but I often see > that routers that are fully capable of routing X Mbps get into issues when > trying to source and/or sink the same X Mbps, so it becomes essential to > monitor router "load" while running tests (something that is also still on > the TODO list for cake-autorate, we should throttle our shapers if the > traffic load exceeds a router's capability to schedule CPU slots timely to > the shaper qdiscs). > >> Better may be to have that router also run ptp4l or equivalent and behave as >> a PTP grandmaster. > > [SM] In OpenWrt it is simple to enable an NTP server would it not be > enough to feed that server via PTP? Otherwise the router would need to > include the high precision clock. And as much as I love my GPS disciplined > NTP server, I have reservations whether I think it a great idea to make GPS > receivers a default router feature (I think this will play into the hand of > location restricted internet access/offering which could easily be abused* > and unlike geoIP it might be tempting to use that information at court as > well). > >> Unfortunately, my day job requires me to focus on "shareholder interests" >> and, in that context, it's very difficult to provide public goods that are >> nonrivalrous and nonexcludable. hxxps://tinyurl.com/mr63p52k >> >> Finally, we all have to deal with "why we sleep" in order to be most >> productive (despite what Mr. Musk thinks.) >> >> hxxps://en.wikipedia.org/wiki/Why_We_Sleep >> >> and there are only so many "awake hours" for us "non-exceptional" engineers >> ;-) (A joke, everybody has value by my book.) > > [SM] ;) the time-limit also applies for non-engineers as well > (independent of exceptions). Fun fact, for most measures most of us fall into > the non-exceptional category anyway. > > Regards > Sebastian > > P.S.: Getting iperf2 into OpenWrt and offering a howto how to make that > available to the outside would be great (as would easy recipes how to install > iperf2 on containers or VPS). I admit however that I did not do my research > here and both howto and recipes might already exist. And again this is not > intended as something for your "plate"/TODO list just as relative simple/low > cost/low effort ways to make iperf2 more salient generally. > > >> >> Thanks, >> Bob _______________________________________________ LibreQoS mailing list LibreQoS@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/libreqos
