*BSD News Article 2167


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From: rpw3@rigden.wpd.sgi.com (Rob Warnock)
Newsgroups: comp.unix.bsd
Subject: Re: 386bsd 0.1: non-reciprical ftp performance.
Message-ID: <nio1lgs@sgi.sgi.com>
Date: 21 Jul 92 11:50:03 GMT
Sender: rpw3@rigden.wpd.sgi.com
Organization: Silicon Graphics, Inc.  Mountain View, CA
Lines: 24

greg@ecse.rpi.edu (Greg) writes:
+---------------
|    In a previous post,  I complained of sluggish ftp performance (6-7 kb/sec).
| I discovered later that I can ftp files to a sun sparcstation ipc and get 
| 120-130 kb/sec. Ftping files from the same machine still yeilds only
| 6-7 kb/sec. This is quite repeatable.
+---------------

Such asymmetrical performances often indicate a TCP protocol mismatch. I'm
not sure what window sizes 386bsd is offering to the Sun, but I'm guessing
that the "Net-2" delayed-ACK code may be hanging you up. Try FTP from a
machine running a more recent TCP, and see if the problem goes away.

(We at SGI saw similar problems when we our new TCP increased its default
offered window. Suddenly some older TCPs started misbehaving.)


-Rob

-----
Rob Warnock, MS-9U/510		rpw3@sgi.com
Silicon Graphics, Inc.		(415)390-1673
2011 N. Shoreline Blvd.
Mountain View, CA  94043