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From: David Lang <david@lang.hm>
To: Michal Kazior <michal.kazior@tieto.com>
Cc: Dave Taht <dave.taht@gmail.com>,
	make-wifi-fast@lists.bufferbloat.net,
	"codel@lists.bufferbloat.net" <codel@lists.bufferbloat.net>
Subject: Re: [Codel] [Make-wifi-fast] [RFC/RFT] mac80211: implement fq_codel for software queuing
Date: Mon, 21 Mar 2016 18:29:53 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.02.1603211827190.26766@nftneq.ynat.uz> (raw)
In-Reply-To: <CA+BoTQk37=KH+q89FTKgve0-yJ+ChiZGvVbGC39-aNpre9JShg@mail.gmail.com>

On Mon, 29 Feb 2016, Michal Kazior wrote:

>> Our intent is to continue to improve the flent test suite to be able
>> to generate repeatable tests, track relevant wifi behaviors and pull
>> relevant data back, graphed over time (of test) and time (over test
>> runs). A problem with udp flood tests is that tcp traffic is always
>> bidirectional (data vs acks), so a naive thought would be, that yes,
>> you should get half the bandwidth you get with a udp flood test.
>
> I don't see why you'd be doomed to get only half the bandwidth because
> of that? Sure, Wi-Fi is half-duplex but transmit time for ACKs is a
> lot smaller than transmit time for the data.

The difference is actually far less than you think. Each transmission has a 
fixed-length header and quiet times that were designed in the days of 802.11b 
(1-11Mb) and if you are transmitting a wide 802.11ac signal at a couple hundred 
Mb, you can find that the time taken to transmit even full packets is a 
surprisingly small percentage of the total transmit time.

David Lang

  reply	other threads:[~2016-03-22  1:29 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1456492163-11437-1-git-send-email-michal.kazior@tieto.com>
2016-02-26 14:32 ` [Codel] Fwd: " Dave Taht
2016-02-26 19:27   ` [Codel] " Michal Kazior
2016-02-26 22:20     ` Dave Taht
2016-02-29 12:35       ` Michal Kazior
2016-03-22  1:29         ` David Lang [this message]
2016-03-22  3:14           ` [Codel] [Make-wifi-fast] " Aaron Wood

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