Netdev List
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: "John A. Sullivan III" <jsullivan@opensourcedevel.com>
Cc: netdev@vger.kernel.org
Subject: Re: Shaping TCP ACK packets
Date: Tue, 06 Dec 2011 06:59:26 +0100	[thread overview]
Message-ID: <1323151166.2467.11.camel@edumazet-laptop> (raw)
In-Reply-To: <7cf7b0f6-b30f-465a-9e50-20bd2c31bbe9@jasiiieee>

Le lundi 05 décembre 2011 à 23:18 -0500, John A. Sullivan III a écrit :
> Hello, all.  I've seen several sites recommend prioritizing TCP ACK
> packets using tc.  Is that a good idea? I have two reservations:
> 
> 1) If my line is congested, isn't delaying ACKs a good way to slow
> down the conversation? Accelerating ACKs under congestion sounds a bit
> like stuffing more food in my mouth when I'm already choking.
> 
It depends which way is congested. Sites recommends prioritizing ACKS on
the up way, because most of the time ADSL links are assymetric. an
uplink is congested.


> 2) By messing with normal coordination of TCP, do I risk making a
> mess.  Specifically, can I create problems with out of order packet
> delivery - send an ACK before the packet which should have preceded
> it? I suppose in a well behaved protocol that wouldn't happen but I'm
> not sure.  Thanks - John
> --

Well, if you prioritize true acks (packets with no payload), there is no
reorder problem per se.

      reply	other threads:[~2011-12-06  5:59 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <b7c7ae97-0030-4397-a1e3-ec29babdff4d@jasiiieee>
2011-12-06  4:18 ` Shaping TCP ACK packets John A. Sullivan III
2011-12-06  5:59   ` Eric Dumazet [this message]

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

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1323151166.2467.11.camel@edumazet-laptop \
    --to=eric.dumazet@gmail.com \
    --cc=jsullivan@opensourcedevel.com \
    --cc=netdev@vger.kernel.org \
    /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