From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ej1-x62e.google.com (mail-ej1-x62e.google.com [IPv6:2a00:1450:4864:20::62e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 4B7953B2A4 for ; Wed, 29 Apr 2020 20:32:19 -0400 (EDT) Received: by mail-ej1-x62e.google.com with SMTP id re23so3189400ejb.4 for ; Wed, 29 Apr 2020 17:32:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=TcRVinXPchoWNQ4XvqMvrxQZN6X4HZROIbQIiBV1vlM=; b=afMBrIN4tT3H2mYsqMZC8T0ZgLpz+RyHi3BkeUo+UT+eA2NlbQAJOaa9cjk3L4HMwT xrO0AOjAd7hrMB7gVhjlzrZ1dM11xzm42fF5WW5Zt3xvTd6t8vq65AWbrY4sN7XKTQwM QWSmKs8tIO8jbjUCWf8td0s0IE4CjhSYOkcfk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=TcRVinXPchoWNQ4XvqMvrxQZN6X4HZROIbQIiBV1vlM=; b=F4kIrselES+JgWmsF0Lmig/VeH9Q/AeYimwJW4SJfUMc0nJq0UDyli/a7JUV/cmgPG 0Ius6O6LnCYq1tSitNtxAtT1UMxfwM87G58ae7C0sDG2D7iguTvVWvEr507NSloTihmC q71hQEo/opZ/+uK8c3ydVYuz7lus8DvjiKGnMoW2atClYCbVwPynykN0DUrHNZdoq5P6 r7+OPNjlT+pmrmKd2jnCRVal07mWRwwaVQwG+HWBIpCwaMMGoN2LJSpKQ09QXkc3U+10 cEt4HQ5HNMVAhqZb5/6HQfVKmHgAtGbCZAveyEaXYL1IlbFq4RZ68nR1TAksv8/vlljR JulQ== X-Gm-Message-State: AGi0PuaL4jmg1jXBsLm13EQV9Ee9L9xm97okOcxIv4asO2u6DETBM1nx nplospAVx0Vm6d8LoEv+9FvBljan2M/8LUUPY+Lliw== X-Google-Smtp-Source: APiQypKh55qFz4sNDe2AtAfuSVOOu2OHpqq7DMDLd1DPJMJoJi/cUakKADXWqjKZ9yCD0espTEBB8MI6cPvYgNQlzu8= X-Received: by 2002:a17:906:edc2:: with SMTP id sb2mr331481ejb.129.1588206738300; Wed, 29 Apr 2020 17:32:18 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Bob McMahon Date: Wed, 29 Apr 2020 17:32:07 -0700 Message-ID: Subject: Re: [Make-wifi-fast] Uplink vs downlink latency To: Dave Taht Cc: Tim Higgins , Make-Wifi-fast Content-Type: multipart/alternative; boundary="00000000000077b48605a4773220" X-List-Received-Date: Thu, 30 Apr 2020 00:32:19 -0000 --00000000000077b48605a4773220 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable I'm thinking ping may not be ideal for benchmarking OFDMA effects on latency. Also, the end/end latency preferred seems to me the socket write() to final socket read() per that write(). Also, for TCP, there are the connect times. I realize network stack guys focus on stack related measurements, e.g. RTT, but the latencies users experience include the application level and system level os interactions. Just some food or thought. Bob On Wed, Apr 29, 2020 at 5:07 PM Dave Taht wrote: > throughput and latency are interrelated, whats the throughput? > > On Wed, Apr 29, 2020 at 2:40 PM Tim Higgins > wrote: > > > > Hi all, > > > > I finally have my testbed working the way I want and am starting to run > tests to see if OFDMA does anything useful. > > > > This will all be covered in detail in an upcoming SmallNetBuilder > article. But I wanted to sanity check something with this esteemed group. > > > > The tests are basically the flent rtt_fair_var up and down tests ported > to the octoScope platform I use for WiFi testing. > > The initial work was done on flent, with a lot of hand-holding from > Toke. (Thank you, Toke!) > > > > Using 4 Intel AX200 STAs on Win10. iperf3 is running traffic using > TCP/IP with unthrottled bandwidth. I've taken Bj=C3=B8rn's idea and have = each > STA using a different DSCP priority level, but with TCP/IP traffic, not > UDP. I'm sticking to using CS0-7 equivalents and confirmed that the iperf= 3 > --dscp values properly translate to the intended WiFi priority levels. > Each STA has a different priority, either CS0,3,5 or 6 (best effort, > excellent effort, video and voice). > > > > Ping is used to measure latency and always runs from AP to STA. Only > TCP/IP traffic direction is reversed between the down and uplink tests. > > > > One thing that jumps out immediately is that uplink latencies are *much= * > lower than downlink, with either OFDMA on or off. Attached are three > examples. The CDFs are average latency of the 4 STAs. > > > > The NETGEAR R7800 is a 4x4 AC Qualcomm-based. I'm using this as a > baseline product. > > > > The NETGEAR RAX15 is 2x2 AX Broadcom-based. You can see what I mean whe= n > I say OFDMA doesn't help. > > > > Does this much difference between up and downlink latency pass the snif= f > test? > > > > =3D=3D=3D > > Tim > > _______________________________________________ > > Make-wifi-fast mailing list > > Make-wifi-fast@lists.bufferbloat.net > > https://lists.bufferbloat.net/listinfo/make-wifi-fast > > > > -- > Make Music, Not War > > Dave T=C3=A4ht > CTO, TekLibre, LLC > http://www.teklibre.com > Tel: 1-831-435-0729 > _______________________________________________ > Make-wifi-fast mailing list > Make-wifi-fast@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/make-wifi-fast --00000000000077b48605a4773220 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I'm thinking ping may not be ideal for benchmarking=C2= =A0OFDMA effects on latency.=C2=A0 Also, the end/end latency preferred seem= s to me the socket write() to final socket read() per that write(). Also, f= or TCP, there are the connect times. I realize network stack guys focus on = stack related measurements, e.g. RTT, but the latencies users experience in= clude the application level and system level os interactions.

Just s= ome food=C2=A0or thought.

Bob


On Wed, Apr 29, 2020 at 5:07 PM= Dave Taht <dave.taht@gmail.com> wrote:
th= roughput and latency are interrelated, whats the throughput?

On Wed, Apr 29, 2020 at 2:40 PM Tim Higgins <tim@smallnetbuilder.com> wrote: >
> Hi all,
>
> I finally have my testbed working the way I want and am starting to ru= n tests to see if OFDMA does anything useful.
>
> This will all be covered in detail in an upcoming SmallNetBuilder arti= cle. But I wanted to sanity check something with this esteemed group.
>
> The tests are basically the flent rtt_fair_var up and down tests porte= d to the octoScope platform I use for WiFi testing.
> The initial work was done on flent, with a lot of hand-holding from To= ke. (Thank you, Toke!)
>
> Using 4 Intel AX200 STAs on Win10. iperf3 is running traffic using TCP= /IP with unthrottled bandwidth. I've taken Bj=C3=B8rn's idea and ha= ve each STA using a different DSCP priority level, but with TCP/IP traffic,= not UDP. I'm sticking to using CS0-7 equivalents and confirmed that th= e iperf3 --dscp values properly translate to the intended WiFi priority lev= els.=C2=A0 Each STA has a different priority, either CS0,3,5 or 6 (best eff= ort, excellent effort, video and voice).
>
> Ping is used to measure latency and always runs from AP to STA. Only T= CP/IP traffic direction is reversed between the down and uplink tests.
>
> One thing that jumps out immediately is that uplink latencies are *muc= h* lower than downlink, with either OFDMA on or off. Attached are three exa= mples. The CDFs are average latency of the 4 STAs.
>
> The NETGEAR R7800 is a 4x4 AC Qualcomm-based. I'm using this as a = baseline product.
>
> The NETGEAR RAX15 is 2x2 AX Broadcom-based. You can see what I mean wh= en I say OFDMA doesn't help.
>
> Does this much difference between up and downlink latency pass the sni= ff test?
>
> =3D=3D=3D
> Tim
> _______________________________________________
> Make-wifi-fast mailing list
> Make-wifi-fast@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/ma= ke-wifi-fast



--
Make Music, Not War

Dave T=C3=A4ht
CTO, TekLibre, LLC
ht= tp://www.teklibre.com
Tel: 1-831-435-0729
_______________________________________________
Make-wifi-fast mailing list
M= ake-wifi-fast@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/make-wif= i-fast
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