From: Dave Taht <dave.taht@gmail.com>
To: Tim Higgins <tim@smallnetbuilder.com>
Cc: Make-Wifi-fast <make-wifi-fast@lists.bufferbloat.net>
Subject: Re: [Make-wifi-fast] Uplink vs downlink latency
Date: Wed, 29 Apr 2020 17:06:50 -0700 [thread overview]
Message-ID: <CAA93jw5WRJMfmvN3ZUKJ70v3i_BuLjda+QZx8ChfOekvkFPKGA@mail.gmail.com> (raw)
In-Reply-To: <da55c8d4-61e7-203c-0854-45a12894f12b@smallnetbuilder.com>
throughput 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 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 Bjørn'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. 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?
>
> ===
> 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 Täht
CTO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-831-435-0729
next prev parent reply other threads:[~2020-04-30 0:07 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-29 21:40 Tim Higgins
2020-04-29 23:55 ` Isaac Konikoff
2020-04-30 14:02 ` Tim Higgins
2020-04-30 0:06 ` Dave Taht [this message]
2020-04-30 0:32 ` Bob McMahon
2020-04-30 14:18 ` Tim Higgins
2020-04-30 15:58 ` Dave Taht
2020-04-30 14:13 ` Tim Higgins
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