[1095] in linux-net channel archive
slow start problem Linux/HPUX
daemon@ATHENA.MIT.EDU (Olaf Kirch)
Wed Sep 13 05:49:19 1995
To: linux-net@vger.rutgers.edu
Reply-To: okir@monad.swb.de
Date: Tue, 12 Sep 1995 13:55:21 +0200
From: Olaf Kirch <ok@daveg.com>
Hello,
I have a problem with TCP slow start getting in my way when a Linux box
speaks to an HPUX box (at least I believe it's slow start). The
application samples a pointer device, and continuously sends
XWarpPointer requests to a remote X server on the same Ethernet.
Right after startup, response is very sluggish. Watching with tcpdump
shows that initially Linux passses only about three packets before
waiting for an ACK. After a minute or so, it has bumped the congestion
window to about 20, which provides a reasonably smooth pointer movement.
Interestingly, the HP box seems to send ACKs at a constant rate of about
5 per second.
I feel a little stuck with this problem now, because I neither see how
the application could make Linux's slow start a little faster, nor
how I could make the HP box send its ACKs more rapidly. (FWIW, TCP_NODELAY
is on). Any ideas?
The PC is running Linux 1.3.15; the HP box runs HPUX 9.03.
Cheers
Olaf
