From: kuznet@ms2.inr.ac.ru
To: lk@tantalophile.demon.co.uk (Jamie Lokier)
Cc: davem@redhat.com, ak@muc.de, linux-kernel@vger.kernel.org
Subject: Re: Excessive TCP retransmits over lossless, high latency link
Date: Sat, 1 Sep 2001 23:20:09 +0400 (MSK DST) [thread overview]
Message-ID: <200109011920.XAA20031@ms2.inr.ac.ru> (raw)
In-Reply-To: <20010901195532.B2714@thefinal.cern.ch> from "Jamie Lokier" at Sep 1, 1 07:55:32 pm
Hello!
> binary trace with "tcpdump -n -w" is attached,
I am afraid you forgot it.
> I am wondering if not sending so many duplicate ACKs would help the
> broken sender (I know, that is against RFC793 but hey if it works...).
If it works, hack kernel not to send dupacks. What is the problem? :-)
Yes, on such links fast retransmit is not useful in any case.
Actually, you can make something from your side: if rtt is so high,
most likely this means excessive queueing. You can fight this
advertising smaller window (f.e. adding option "window N" to route).
If intepacket gap is 5sec and rtt 23, you can divide window by 23/5
and rtt should drop to some more reasonable number. "Theoretical"
bandwidth will reduce, but practical will grow.
> For the sake of a Linux test, I shall try proxying this stream via a
> Linux 2.4.2 box I have on the net, and see if it is an improvement.
Yes, it is intersting.
Alexey
next prev parent reply other threads:[~2001-09-01 19:20 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-09-01 17:17 Excessive TCP retransmits over lossless, high latency link Jamie Lokier
2001-09-01 17:41 ` Andi Kleen
2001-09-01 18:12 ` kuznet
2001-09-01 18:22 ` Jamie Lokier
2001-09-01 19:07 ` Neil Spring
2001-09-01 18:08 ` kuznet
2001-09-01 18:55 ` Jamie Lokier
2001-09-01 19:20 ` kuznet [this message]
2001-09-01 20:02 ` Jamie Lokier
2001-09-01 20:39 ` Lukas Beeler
2001-09-03 17:14 ` kuznet
2001-09-03 17:57 ` Jamie Lokier
2001-09-03 18:07 ` kuznet
2001-09-01 19:59 ` Alan Cox
[not found] <20010901195532.B2714@thefinal.cern.ch.suse.lists.linux.kernel>
[not found] ` <200109011920.XAA20031@ms2.inr.ac.ru.suse.lists.linux.kernel>
[not found] ` <20010901210212.A3361@thefinal.cern.ch.suse.lists.linux.kernel>
[not found] ` <20010901223918.A4053@mail.projectdream.org.suse.lists.linux.kernel>
2001-09-01 21:45 ` Andi Kleen
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=200109011920.XAA20031@ms2.inr.ac.ru \
--to=kuznet@ms2.inr.ac.ru \
--cc=ak@muc.de \
--cc=davem@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lk@tantalophile.demon.co.uk \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.