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Cc: Hal Murray <hmurray@megapathdsl.net>, bloat <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] SO_SNDBUF and SO_RCVBUF
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On Thu, 2015-04-23 at 21:37 -0700, Dave Taht wrote:
> On Wed, Apr 22, 2015 at 2:05 PM, Rick Jones <rick.jones2@hp.com> wrote:
> > On 04/22/2015 02:02 PM, Eric Dumazet wrote:
> >>
> >> Yeah, the real nice thing is TCP_NOTSENT_LOWAT added in linux-3.12
> 
> I will argue that that would give a much better estimate as to how
> much data was really outstanding on the wire.

This would be the responsibility of the CC.

Each CC has its own ways to be controlled. vegas & cubic have different
knobs.

TCP_NOTSENT_LOWAT controls the number of unsent bytes. This is generic.

You do not want to add a 'knob' that would lock all CC to a given
behavior : It is already there with pacing.

If you know the rtt, then with pacing you also can limit XXX bytes on
the wire.