One of my long concerns with the RRUL test is that the ICMP ping test
portion is not isochronous, and runs at a variable rate based on rtt, which
means that it uses more/less bandwidth as an inverse function of rtt, and
that makes it harder to compare the actual goodput of the tcp streams
running in parallel.  (When the top-line total bw goes down when latency
goes down, because the icmp and udp ping tests are using more bandwidth
that isn’t accounted for in the bw totals)

On Sat, Mar 27, 2021 at 2:45 PM Dave Taht <dave.taht@gmail.com> wrote:

> most of the latency related portions of flent use irtt, which I think
> is a lot more solid than anything else.
>
> On Sat, Mar 27, 2021 at 2:44 PM Dave Taht <dave.taht@gmail.com> wrote:
> >
> > so glad to hear the license has been fixed.
> >
> > carl, iperf is only used in a few of flent's tests. We trusted netperf
> > - as did the linux kernel developers - a lot further than all the
> > iperf variants combined - at the time we started work on flent.
> >
> > I would not mind us somehow developing a drop in replacement for
> > netperf, perhaps leveraging the irtt codebase, as I have a long
> > standing desire to be able to reliably measure latencies and the
> > output of TCP_INFO in "some" tool below 250us.
> >
> > iperf has come a long way, but getting to where I could trust the
> > largely "academic" codebase it was would take a ton of benchmarking.
> >
> > On Sat, Mar 27, 2021 at 2:09 PM Klatsky, Carl via Bloat
> > <bloat@lists.bufferbloat.net> wrote:
> > >
> > > Toke,
> > >
> > > How you see this coming into Flent?  My understanding is that for
> latency & load test like RRUL:
> > >
> > > -iperf provides the bandwidth portion
> > > -IRTT provides the latency portion, and if IRTT is not found, the test
> falls back to ICMP for the latency check
> > >
> > > Would netperf replace iperf for the bandwidth portion?  Do you see it
> being used for the latency portion?
> > >
> > > Thanks,
> > > Carl
> > >
> > > -----Original Message-----
> > > From: Bloat <bloat-bounces@lists.bufferbloat.net> On Behalf Of Toke
> Høiland-Jørgensen via Bloat
> > > Sent: Friday, March 26, 2021 7:32 PM
> > > To: bloat <bloat@lists.bufferbloat.net>
> > > Subject: [Bloat] Netperf re-licensed as MIT
> > >
> > > Hopefully this means we can get it packaged for the distros that have
> thus far refused to because of the license - i.e., Debian and Fedora!
> > >
> > > -Toke
> > > _______________________________________________
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> > > Bloat@lists.bufferbloat.net
> > >
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> >
> >
> >
> > --
> > "For a successful technology, reality must take precedence over public
> > relations, for Mother Nature cannot be fooled" - Richard Feynman
> >
> > dave@taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729
>
>
>
> --
> "For a successful technology, reality must take precedence over public
> relations, for Mother Nature cannot be fooled" - Richard Feynman
>
> dave@taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729
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