From: Juliusz Chroboczek <jch@irif.fr>
To: Jan Ceuleers <jan.ceuleers@gmail.com>
Cc: bloat@lists.bufferbloat.net
Subject: Re: [Bloat] [Make-wifi-fast] benefits of ack filtering
Date: Sun, 03 Dec 2017 14:57:17 +0100 [thread overview]
Message-ID: <87po7vud6q.wl-jch@irif.fr> (raw)
In-Reply-To: <f2933f6d-85ef-3223-22ce-0ae3adba9c37@gmail.com>
>> I'm lost here. What exact problem is the ACK hack supposed to work
>> around? Ridiculous amount of asymmetry in the last-hop WiFi link, or
>> outrageous amounts of asymmetry in a transit link beyond the last hop?
> My understanding is that the issue that gave rise to this discussion was
> concerned with upstream bandwidth conservation in the uplink of a DOCSIS
> network by the cable modem dropping a large percentage of upstream TCP ACKs.
Ok, that's what I thought. I'm glad we agree that WiFi is a different issue.
A TCP Ack is 40 bytes. A data packet is up to 1500 bytes.
As far as I know, DOCSIS has an asymmetry factor that is between 4 and 10,
depending on the deployment. With worst case asymmetry being 10, this
means that you can send an Ack for every data packet with 400 byte data
packets, every second data packet with 200 byte data packets. If the
asymmetry is a more reasonable 4, then the figures are 100 and 50
respectively.
Try as I might, I fail to see the problem. Are we advocating deploying
TCP-aware middleboxes, with all the problems that entails, in order to
work around a problem that doesn't exist?
-- Juliusz
next prev parent reply other threads:[~2017-12-03 13:57 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-28 21:48 [Bloat] " Dave Taht
2017-11-29 6:09 ` Mikael Abrahamsson
2017-11-29 9:34 ` Sebastian Moeller
2017-11-29 12:49 ` Mikael Abrahamsson
2017-11-29 13:13 ` Luca Muscariello
2017-11-29 14:31 ` Mikael Abrahamsson
2017-11-29 14:36 ` Jonathan Morton
2017-11-29 15:24 ` Andrés Arcia-Moret
2017-11-29 15:53 ` Luca Muscariello
[not found] ` <CAJq5cE3qsmy8EFYZmQsLL_frm8Tty9Gkm92MQPZ649+kpM1oMw@mail.gmail.com>
2017-11-29 16:13 ` Jonathan Morton
2017-11-30 7:03 ` Michael Welzl
2017-11-30 7:24 ` Dave Taht
2017-11-30 7:45 ` Dave Taht
2017-11-30 7:48 ` Jonathan Morton
2017-11-30 8:00 ` Luca Muscariello
2017-11-30 10:24 ` Eric Dumazet
2017-11-30 13:04 ` Mikael Abrahamsson
2017-11-30 15:51 ` Eric Dumazet
2017-12-01 0:28 ` David Lang
2017-12-01 7:09 ` Jan Ceuleers
2017-12-01 12:53 ` Toke Høiland-Jørgensen
2017-12-01 13:13 ` [Bloat] [Make-wifi-fast] " Кирилл Луконин
2017-12-01 13:22 ` Luca Muscariello
2017-12-11 17:42 ` Simon Barber
2017-12-01 13:17 ` [Bloat] " Luca Muscariello
2017-12-01 13:40 ` Toke Høiland-Jørgensen
2017-12-01 17:42 ` Dave Taht
2017-12-01 20:39 ` Juliusz Chroboczek
2017-12-03 5:20 ` [Bloat] [Make-wifi-fast] " Bob McMahon
2017-12-03 10:35 ` Juliusz Chroboczek
2017-12-03 11:40 ` Jan Ceuleers
2017-12-03 13:57 ` Juliusz Chroboczek [this message]
2017-12-03 14:07 ` Mikael Abrahamsson
2017-12-03 19:53 ` Juliusz Chroboczek
2017-12-03 14:09 ` Ryan Mounce
2017-12-03 19:54 ` Juliusz Chroboczek
2017-12-03 20:14 ` Sebastian Moeller
2017-12-03 22:27 ` Dave Taht
2017-12-03 15:25 ` Robert Bradley
2017-12-04 3:44 ` Dave Taht
2017-12-04 14:38 ` David Collier-Brown
2017-12-04 15:44 ` Juliusz Chroboczek
2017-12-04 17:17 ` David Collier-Brown
2017-12-03 19:04 ` Bob McMahon
2017-12-01 21:17 ` Bob McMahon
2017-12-01 8:45 ` [Bloat] " Sebastian Moeller
2017-12-01 10:45 ` Luca Muscariello
2017-12-01 18:43 ` Dave Taht
2017-12-01 18:57 ` Luca Muscariello
2017-12-01 19:36 ` Dave Taht
2017-11-30 14:51 ` Neal Cardwell
2017-11-30 15:55 ` Eric Dumazet
2017-11-30 15:57 ` Neal Cardwell
2017-11-29 16:50 ` Sebastian Moeller
2017-12-12 19:27 ` Benjamin Cronce
2017-12-12 20:04 ` Dave Taht
2017-12-12 21:03 ` David Lang
2017-12-12 21:29 ` Jonathan Morton
2017-12-12 22:03 ` Jonathan Morton
2017-12-12 22:21 ` David Lang
[not found] ` <CAJq5cE3nfSQP0GCLjp=X0T-iHHgAs=YUCcr34e3ARgkrGZe-wg@mail.gmail.com>
2017-12-12 22:41 ` Jonathan Morton
2017-12-13 9:46 ` Mikael Abrahamsson
2017-12-13 10:03 ` Jonathan Morton
2017-12-13 12:11 ` Sebastian Moeller
2017-12-13 12:18 ` Jonathan Morton
2017-12-13 12:36 ` Sebastian Moeller
2017-12-13 12:39 ` Luca Muscariello
2017-11-29 18:21 ` Juliusz Chroboczek
2017-11-29 18:41 ` Dave Taht
2017-11-29 23:29 ` Steinar H. Gunderson
2017-11-29 23:59 ` Stephen Hemminger
2017-11-30 0:21 ` Eric Dumazet
2017-12-11 20:15 ` Benjamin Cronce
2017-11-29 18:28 ` Juliusz Chroboczek
2017-11-29 18:48 ` Dave Taht
2017-12-11 18:30 ` Jonathan Morton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://lists.bufferbloat.net/postorius/lists/bloat.lists.bufferbloat.net/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87po7vud6q.wl-jch@irif.fr \
--to=jch@irif.fr \
--cc=bloat@lists.bufferbloat.net \
--cc=jan.ceuleers@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox