From: Eric Dumazet <eric.dumazet@gmail.com>
To: Jonathan Morton <chromatix99@gmail.com>
Cc: "Steinar H. Gunderson" <sgunderson@bigfoot.com>,
Neal Cardwell <ncardwell@google.com>,
"aqm@ietf.org" <aqm@ietf.org>,
bloat <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] TCP BBR paper is now generally available
Date: Sat, 03 Dec 2016 13:07:40 -0800 [thread overview]
Message-ID: <1480799260.18162.418.camel@edumazet-glaptop3.roam.corp.google.com> (raw)
In-Reply-To: <9A821B94-143B-446F-8852-2EB0158DD57C@gmail.com>
On Sat, 2016-12-03 at 22:26 +0200, Jonathan Morton wrote:
> > On 3 Dec, 2016, at 22:20, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> >
> > Huge ACK decimation it seems.
>
> That extract does not show ACK decimation. It shows either jumbo
> frames or offload aggregation in a send burst, and ordinary
> delayed-acks each covering at most two packets received. Nothing
> particularly weird or unusual appears to be happening in the network.
I do not attend IETF meetings so maybe my words are not exact.
What I meant was that we receive ACKS in bursts, with huge gaps between
them.
Look at tsval/tsecr, and that all ACKS are received in a 20 usec time
window, covering data that was sent in a 5 ms window.
Looks the reverse path is severely congested or a device does ack
filtering.
11:14:05.468643 IP6 C > S: Flags [.], ack 364280308, win 23430, options [nop,nop,TS val 864456877 ecr 3498315454], length 0
11:14:05.468645 IP6 C > S: Flags [.], ack 364288528, win 23407, options [nop,nop,TS val 864456877 ecr 3498315454], length 0
11:14:05.468646 IP6 C > S: Flags [.], ack 364296748, win 23415, options [nop,nop,TS val 864456877 ecr 3498315455], length 0
11:14:05.468648 IP6 C > S: Flags [.], ack 364302460, win 23400, options [nop,nop,TS val 864456877 ecr 3498315455], length 0
11:14:05.468650 IP6 C > S: Flags [.], ack 364304968, win 23430, options [nop,nop,TS val 864456877 ecr 3498315455], length 0
<huge gap>
11:14:05.510870 IP6 C > S: Flags [.], ack 364313188, win 23407, options [nop,nop,TS val 864456877 ecr 3498315455], length 0
11:14:05.510885 IP6 C > S: Flags [.], ack 364321408, win 23415, options [nop,nop,TS val 864456877 ecr 3498315455], length 0
11:14:05.510888 IP6 C > S: Flags [.], ack 364328548, win 23396, options [nop,nop,TS val 864456877 ecr 3498315455], length 0
11:14:05.510890 IP6 C > S: Flags [.], ack 364335340, win 23419, options [nop,nop,TS val 864456877 ecr 3498315455], length 0
11:14:05.510892 IP6 C > S: Flags [.], ack 364337848, win 23430, options [nop,nop,TS val 864456877 ecr 3498315456], length 0
11:14:05.510894 IP6 C > S: Flags [.], ack 364353208, win 23389, options [nop,nop,TS val 864456877 ecr 3498315456], length 0
11:14:05.510895 IP6 C > S: Flags [.], ack 364362508, win 23411, options [nop,nop,TS val 864456877 ecr 3498315456], length 0
11:14:05.510897 IP6 C > S: Flags [.], ack 364370728, win 23415, options [nop,nop,TS val 864456877 ecr 3498315456], length 0
11:14:05.510899 IP6 C > S: Flags [.], ack 364378948, win 23419, options [nop,nop,TS val 864456877 ecr 3498315456], length 0
11:14:05.510900 IP6 C > S: Flags [.], ack 364384660, win 23404, options [nop,nop,TS val 864456877 ecr 3498315457], length 0
11:14:05.510902 IP6 C > S: Flags [.], ack 364387168, win 23430, options [nop,nop,TS val 864456877 ecr 3498315457], length 0
11:14:05.510904 IP6 C > S: Flags [.], ack 364394308, win 23411, options [nop,nop,TS val 864456877 ecr 3498315457], length 0
11:14:05.510905 IP6 C > S: Flags [.], ack 364403608, win 23411, options [nop,nop,TS val 864456877 ecr 3498315457], length 0
11:14:05.510907 IP6 C > S: Flags [.], ack 364411828, win 23419, options [nop,nop,TS val 864456878 ecr 3498315457], length 0
next prev parent reply other threads:[~2016-12-03 21:07 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-02 15:52 Dave Taht
2016-12-02 19:15 ` Aaron Wood
2016-12-02 20:32 ` Jonathan Morton
2016-12-02 22:22 ` Neal Cardwell
2016-12-02 22:40 ` Steinar H. Gunderson
2016-12-02 23:31 ` Eric Dumazet
2016-12-03 13:03 ` Neal Cardwell
2016-12-03 19:13 ` Steinar H. Gunderson
2016-12-03 20:20 ` Eric Dumazet
2016-12-03 20:26 ` Jonathan Morton
2016-12-03 21:07 ` Eric Dumazet [this message]
2016-12-03 21:34 ` Steinar H. Gunderson
2016-12-03 21:50 ` Eric Dumazet
2016-12-03 22:13 ` Steinar H. Gunderson
2016-12-03 22:55 ` Eric Dumazet
2016-12-03 23:02 ` Eric Dumazet
2016-12-03 23:09 ` Eric Dumazet
2016-12-03 23:03 ` Steinar H. Gunderson
2016-12-03 23:15 ` Eric Dumazet
2016-12-03 23:24 ` Eric Dumazet
2016-12-04 3:18 ` Neal Cardwell
2016-12-04 8:44 ` Steinar H. Gunderson
2016-12-04 17:13 ` Eric Dumazet
2016-12-04 17:38 ` Steinar H. Gunderson
2016-12-06 17:20 ` Steinar H. Gunderson
2016-12-06 21:31 ` Neal Cardwell
2016-12-03 21:38 ` Jonathan Morton
2016-12-03 21:33 ` Steinar H. Gunderson
2016-12-07 16:28 ` Alan Jenkins
2016-12-07 16:47 ` Steinar H. Gunderson
2016-12-07 17:03 ` Alan Jenkins
2016-12-08 8:24 ` Mikael Abrahamsson
2016-12-08 13:22 ` Dave Täht
2016-12-08 14:01 ` Mikael Abrahamsson
2016-12-08 21:29 ` Neal Cardwell
2016-12-08 22:31 ` Yuchung Cheng
2016-12-09 14:52 ` Klatsky, Carl
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