From owner-freebsd-stable@FreeBSD.ORG Thu Feb 18 16:01:36 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EAC71106566C for ; Thu, 18 Feb 2010 16:01:36 +0000 (UTC) (envelope-from shurd@sasktel.net) Received: from proton.sasknet.sk.ca (proton.sasknet.sk.ca [142.165.20.178]) by mx1.freebsd.org (Postfix) with ESMTP id B0D598FC16 for ; Thu, 18 Feb 2010 16:01:35 +0000 (UTC) Received: from pps.filterd (proton [127.0.0.1]) by proton.sasknet.sk.ca (8.14.3/8.14.3) with SMTP id o1IFrHhq014578 for ; Thu, 18 Feb 2010 10:01:35 -0600 Received: from bgmpomr1.sasknet.sk.ca (bgmpOMR1.sasknet.sk.ca [142.165.72.22]) by proton.sasknet.sk.ca with ESMTP id m17srv97d-1 for ; Thu, 18 Feb 2010 10:01:35 -0600 Received: from ace.hurd.local (outgoing.bbsdev.net [76.202.204.46]) by bgmpomr1.sasknet.sk.ca (SaskTel eMessaging Service) with ESMTPA id <0KY100J4MOIMIC00@bgmpomr1.sasknet.sk.ca> for freebsd-stable@freebsd.org; Thu, 18 Feb 2010 10:01:34 -0600 (CST) Date: Thu, 18 Feb 2010 08:01:33 -0800 From: Stephen Hurd In-reply-to: <4B7D61DE.2020906@omnilan.de> To: Harald Schmalzbauer Message-id: <4B7D645D.3090104@sasktel.net> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7BIT References: <4B7C1365.9070806@omnilan.de> <70CD649D-7659-4CE2-A16C-49B8C891CB5B@mac.com> <4B7C4066.5040006@omnilan.de> <4B7D3938.1000309@omnilan.de> <4B7D5AC4.9020509@mahan.org> <4B7D61DE.2020906@omnilan.de> User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.1.23) Gecko/20091205 SeaMonkey/1.1.18 Mnenhy/0.7.6.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=1.12.8161:2.4.5, 1.2.40, 4.0.166 definitions=2010-02-18_10:2010-02-06, 2010-02-18, 2010-02-18 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=default score=0 spamscore=0 ipscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=5.0.0-0908210000 definitions=main-1002180108 Cc: freebsd-stable@freebsd.org, Patrick Mahan Subject: Re: RELENG_8 ignoring TCP window size? [Was: Re: Help for TCP understanding wanted, ACK-MSS-Window [Was: Re: best practice to watch TCP parms of established sockets]] X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Feb 2010 16:01:37 -0000 Harald Schmalzbauer wrote: > Some experimental results: > When rsyncing with windows, and FreeBSD is receiver, I see the same > ACK ever two segemnts, but speed is at 72MB/s. > When FreeBSD is sender and Windows is receiver, it looks more I > expected. There are about 20 data segments before a ACK is returned. > And there are TCP Window Update Segments, reflecting smaller receiver > buffers on the windows side. But this happens at a throughput of > 82MB/s!!! So the windows machine is behaving like I understand the TCP > flow control. > Any explanation why the FreeBSD machine seems to ignore window size? IIRC, the delayed ACK RFC requires an ACK at least every second segment.