From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vs1-xe2e.google.com (mail-vs1-xe2e.google.com [IPv6:2607:f8b0:4864:20::e2e]) (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 AAB503B2A4 for ; Wed, 29 Apr 2020 19:55:51 -0400 (EDT) Received: by mail-vs1-xe2e.google.com with SMTP id h30so2637374vsr.5 for ; Wed, 29 Apr 2020 16:55:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=vrZPGjjSS1uf9khP9BNCdUE41gOmglTtGjYhMBGBQzQ=; b=nxYLYlxaWy+2EA3teSevFQQdL7TvY3hudGtFRbwsrx1jIaN2+tP3Fvk9buvTDFqqTe 6b4QHb/OiYIbyxeWsdu9eANYS0d4EDxZ8jGk98sn6lBVd6ct8KW/rKoSm3DOuoHh1TOF Pka2fGC15WJdjA1NZjfZASWw+GFfZCmTHrzXDjHKrg5qVuqyXVQ2lwxb8GjJzk9i0Kka 9FgrK/Dki3/cPhkS8jj9SHP7uOSeEH9ILL9vdY2xh+h4HvpIOQ3W7PJZwP0KuY2W1xdo gESLF0EjWQA6opBUraZoiUzi795Lo2xAseaix6sZT4rqB+qhXiRoB7K5YYekGPktJ+E3 N8cQ== 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=vrZPGjjSS1uf9khP9BNCdUE41gOmglTtGjYhMBGBQzQ=; b=GYQc93Zng7sz+KvNOCvwY5z7jqmYNi+rOwQkCRbS2jzRVjLn/GJTIozmnETNM83nK6 WFbxZez1HE5DCCbT+OgQEV9qHaQ6p+/RhNY3MLxAFWrQUSta0vyb67dUO5Ya8bsEPWiH pOYz5WTLAiArydad05b5fCCpJzY9uC6rfj/iCMNm0UP0fjKXqF6w9E5j9V0v3ptkhw6A FkrNXRrx+CZCSbixkQ3uYaYoGNI7eKwVUr4t1RPhi64DxEeRUzBahkbzUeTxXgckr3+Z 2Hgu1hjw/l4lWNZAdNl8kyj3oF8mRiQdO+FOhc+tksU+XUqosZrM09fn2MoaOC9vgHPJ Sx7Q== X-Gm-Message-State: AGi0PuYRfsVk+Dax6AwOIf3YRys63b261y2f8lb2q6+Z0dB3yxJotc7Y CVgJ4luWJBwt2FI7dIwCC7CpsQ0eps2rw4kRGZ7Srw== X-Google-Smtp-Source: APiQypJkquJggFyMHQBSUHPRCTyP0fQ6Y90m4sLwICAAy8vQDYng1yaMLOTPae2BeHUI2ufYAyW1wnNzkuJb6NFf5wY= X-Received: by 2002:a67:f78c:: with SMTP id j12mr821488vso.196.1588204551072; Wed, 29 Apr 2020 16:55:51 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Isaac Konikoff Date: Wed, 29 Apr 2020 16:55:43 -0700 Message-ID: To: Tim Higgins Cc: Make-Wifi-fast Content-Type: multipart/alternative; boundary="00000000000018eef605a476b09e" Subject: Re: [Make-wifi-fast] Uplink vs downlink latency X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Apr 2020 23:55:51 -0000 --00000000000018eef605a476b09e Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Tim, I know this will probably be in your write-up, but I am curious if you are sniffing the traffic to verify that OFDMA is actually happening by pinning the aid to the monitor interface and using a wireshark display filter radiotap.he.data_1.ppdu_format=3D=3D0x2 to see the HE_MU frames. From my testing it is not something that is automatically in use all the time...it is used as needed per each AP's decision algorithm. I seem to be able to cause OFDMA to happen sometimes when using small payloads with bursty traffic and periods of quiet, but it is not something that I can turn on and just say OFDMA is happening. Also, in my flent tcp_download vs tcp_upload tests I see similar latency values that are both relatively low. I will have to run the rtt_fair_var to see how it compares. Nice use of flent! Looking forward to your write-up. Isaac 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 t= o > 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 ST= A 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 iperf3 --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 baselin= e > product. > > The NETGEAR RAX15 is 2x2 AX Broadcom-based. You can see what I mean when = I > say OFDMA doesn't help. > > Does this much difference between up and downlink latency pass the sniff > test? > > =3D=3D=3D > Tim > _______________________________________________ > Make-wifi-fast mailing list > Make-wifi-fast@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/make-wifi-fast --00000000000018eef605a476b09e Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Tim,

I know this will pro= bably be in your write-up, but I am curious if you are sniffing the traffic= to verify that OFDMA is actually happening by pinning the aid to the monit= or interface and using a wireshark display filter radiotap.he.data_1.ppdu_f= ormat=3D=3D0x2 to see the HE_MU frames. From my testing it is not something= that is automatically in use all the time...it is used as needed per each = AP's decision algorithm. I seem to be able to cause OFDMA to happen som= etimes when using small payloads with bursty traffic and periods of quiet, = but it is not something that I can turn on and just say OFDMA is happening.=

Also, in my flent tcp_download vs tcp_upload test= s I see similar latency values that are both relatively low. I will have to= run the rtt_fair_var to see how it compares.

Nice= use of flent! Looking forward to your write-up.
Isaac
=

On Wed, Apr 29, 2020 at 2:40 PM Tim Higgins <tim@smallnetbuilder.com> wrote:
<= blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-l= eft:1px solid rgb(204,204,204);padding-left:1ex"> =20 =20 =20
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&= #39;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 iperf3 --dscp values properly translate to the intended WiFi priority levels.=C2=A0 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 when I say OFDMA doesn't help.

Does this much difference between up and downlink latency pass the sniff test?

=20
=3D=3D= =3D
Tim
_______________________________________________
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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