From owner-freebsd-hackers Mon Sep 10 13:35:53 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from elvis.mu.org (elvis.mu.org [216.33.66.196]) by hub.freebsd.org (Postfix) with ESMTP id BDC3B37B401 for ; Mon, 10 Sep 2001 13:35:50 -0700 (PDT) Received: by elvis.mu.org (Postfix, from userid 1192) id 908C381D06; Mon, 10 Sep 2001 15:35:45 -0500 (CDT) Date: Mon, 10 Sep 2001 15:35:45 -0500 From: Alfred Perlstein To: Charles Randall Cc: 'Jonathan Lemon' , Julian Elischer , kent@erix.ericsson.se, hackers@freebsd.org Subject: Re: How to force small TCP packets? Message-ID: <20010910153545.T2965@elvis.mu.org> References: <5FE9B713CCCDD311A03400508B8B30130828F421@bdr-xcln.corp.matchlogic.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <5FE9B713CCCDD311A03400508B8B30130828F421@bdr-xcln.corp.matchlogic.com>; from crandall@matchlogic.com on Mon, Sep 10, 2001 at 02:31:57PM -0600 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG (re: testing a client to see if it deals with short messages over a socket) * Charles Randall [010910 15:32] wrote: > Out of curiosity, can ipfw+dummynet do something like this? I've already responded to the poster in private about it because my initial suggestion was wrong (i hadn't read his email thouroughly enough). One way that should work without having to do anything tricky is using setsockopt with SO_RCVBUF to lower the buffer space, this should force the remote side to buffer and reduce the amount of data to be read. I'm still unsure if this is appropriate because the kernel may silently (or loudly) complain about a SO_RCVBUF that appears to be too small. You may be able to also do this by setting the sysctl kern.ipc.maxsockbuf to something small. -- -Alfred Perlstein [alfred@freebsd.org] 'Instead of asking why a piece of software is using "1970s technology," start asking why software is ignoring 30 years of accumulated wisdom.' To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message