[1255] in linux-net channel archive
Re: Asymmetric TCP/PPP performance (very poor receiving TCP)
daemon@ATHENA.MIT.EDU (Robert L Krawitz)
Fri Oct 27 06:52:44 1995
Date: Thu, 26 Oct 1995 18:55:26 -0400
From: Robert L Krawitz <rlk@tiac.net>
to: linux-net@vger.rutgers.edu
In-reply-to: <XAA01288@sys3.pe1chl.ampr.org> (linux@pe1chl.ampr.org)
From: linux@pe1chl.ampr.org (Rob Janssen reading Linux mailinglist)
Date: Wed, 25 Oct 1995 23:16:36 +0100 (MET)
Yes, I have seen this. Linux sends too many ACKs, it should send the
second ACK only when the window increases from 0 (or maybe from a very
small value) when data is read.
The extra flow of ACKs is also very noticible on the (low speed) amateur
packet radio network :-(
I managed to get rid of them with a patch I don't have time to send
right now (in tcp_read_wakeup, if sk->window > MAX_WINDOW / 4 return
just before sending the ack).
However, I'm not sure it is the cause of the problem you are seeing.
Indeed it isn't. What's interesting is that the packets are received
at almost exact 1/4 second intervals from the remote host. I wonder
why that is...
--
Robert Krawitz <rlk@tiac.net> http://www.tiac.net/users/rlk/
Member of the League for Programming Freedom -- mail lpf@uunet.uu.net
Tall Clubs International -- tci-request@aptinc.com or 1-800-521-2512
