From owner-freebsd-current@FreeBSD.ORG Mon Nov 26 07:48:14 2007 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 975B316A419 for ; Mon, 26 Nov 2007 07:48:14 +0000 (UTC) (envelope-from ianf@clue.co.za) Received: from munchkin.clue.co.za (munchkin.clue.co.za [66.219.59.160]) by mx1.freebsd.org (Postfix) with ESMTP id 6157613C4DB for ; Mon, 26 Nov 2007 07:48:14 +0000 (UTC) (envelope-from ianf@clue.co.za) DomainKey-Signature: a=rsa-sha1; q=dns; c=simple; s=20070313; d=clue.co.za; h=Received:Received:Received:To:cc:From:Subject:In-Reply-To:X-Attribution:Date:Message-Id; b=AIhyEDe1cQgEXip1kYxH/qifBuTp75PsAnwFSr7itbRIOMnHB6+C3MSGnN+RYvvFuaz4nUieSPsHdtFcCZKRSdB65VS02lGr+Lp6E0vnjWyS40ArITqWkcR4P3V+9KBI/Lk6QMySj099pI3pUawbMjOhjZJr4VIDUzCrywrgubfXEcvj7sGRMCNxLjlnSOhDetF901W2j1nLSRCKkew3AThieF69biRjC9KlDbyE/xTB4l2wZJUgnr2U3Hub5avD; Received: from uucp by munchkin.clue.co.za with local-rmail (Exim 4.67) (envelope-from ) id 1IwYhM-0001W7-1x; Mon, 26 Nov 2007 07:48:08 +0000 Received: from ianf.clue.co.za ([10.0.0.6] helo=clue.co.za) by urchin.clue.co.za with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.67) (envelope-from ) id 1IwYhF-0002A3-Ef; Mon, 26 Nov 2007 07:48:01 +0000 Received: from localhost ([127.0.0.1] helo=clue.co.za) by clue.co.za with esmtp (Exim 4.68 (FreeBSD)) (envelope-from ) id 1IwYhE-000G7M-7Y; Mon, 26 Nov 2007 09:48:00 +0200 To: Mike Silbersack From: Ian FREISLICH In-Reply-To: Message from Mike Silbersack of "Mon, 26 Nov 2007 01:18:19 CST." <20071126010504.G7699@odysseus.silby.com> X-Attribution: BOFH Date: Mon, 26 Nov 2007 09:48:00 +0200 Message-Id: Cc: Kip Macy , current@freebsd.org Subject: Re: TCP RST+data! X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Nov 2007 07:48:14 -0000 Mike Silbersack wrote: > > On Mon, 26 Nov 2007, Ian FREISLICH wrote: > > > net.inet.tcp.delayed_ack=0 > > net.inet.tcp.rfc1323=1 > > http://www.freislich.nom.za/phone.nodelayedack > > > > net.inet.tcp.delayed_ack=1 > > net.inet.tcp.rfc1323=1 > > http://www.freislich.nom.za/phone.delayedack > > Wow. Wow! WOW! > > The TCP stack on that device amazes me in how poorly it is written. No surprises there. > So it looks like if the phone does not receive an ACK for its data within > .156785-.150649 = .006136 seconds, it gives up on the connection and > closes it! Yet it still manages to send data along with the RST, which is > something that no other TCP stack (in common use) would do. > > My guess is that even coming in from other OSes, you will experience > problems if you go over a link with any noticeable latency. Yet, a colleague managed to configure the phone using his Mac over that very slow link - analog leased line at 28.8kbps. I do occasionally see resets even when not using delayed ack. > Disabling delayed acks when you need to manage this phone looks like the > only option; I don't see anything else that could be changed to better > accomodate this phone. I really hope that the TCP used by this phone is > not used in any other devices. I'm in communication with the vendor, so hopefully this will get fixed. Interestingly, this is one of the few phones that I've been able to interact with web and telnet while it's busy on a call. Guess you win some... and loose some. Thanks for confirming my suspicions. Ian -- Ian Freislich