From owner-freebsd-net@FreeBSD.ORG Sun Aug 10 03:46:47 2014 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 068C1A80 for ; Sun, 10 Aug 2014 03:46:47 +0000 (UTC) Received: from smtp1.multiplay.co.uk (smtp1.multiplay.co.uk [85.236.96.35]) by mx1.freebsd.org (Postfix) with ESMTP id B86242E57 for ; Sun, 10 Aug 2014 03:46:46 +0000 (UTC) Received: by smtp1.multiplay.co.uk (Postfix, from userid 65534) id BB35720E7088A; Sun, 10 Aug 2014 03:46:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.multiplay.co.uk X-Spam-Level: ** X-Spam-Status: No, score=2.2 required=8.0 tests=AWL,BAYES_00,DOS_OE_TO_MX, FSL_HELO_NON_FQDN_1,HELO_NO_DOMAIN,RDNS_DYNAMIC,STOX_REPLY_TYPE autolearn=no version=3.3.1 Received: from r2d2 (82-69-141-170.dsl.in-addr.zen.co.uk [82.69.141.170]) by smtp1.multiplay.co.uk (Postfix) with ESMTPS id 99F6020E70885; Sun, 10 Aug 2014 03:46:34 +0000 (UTC) Message-ID: <59B841E11C214B28A31D842B7CB1136F@multiplay.co.uk> From: "Steven Hartland" To: "John-Mark Gurney" , "Niu Zhixiong" References: <20140809184232.GF83475@funkthat.com> <8AE1AC56-D52F-4F13-AAA3-BB96042B37DD@lurchi.franken.de> <20140809204500.GG83475@funkthat.com> <3F6BC212-4223-4AAC-8668-A27075DC55C2@lurchi.franken.de> <20140810022350.GI83475@funkthat.com> <20140810033212.GL83475@funkthat.com> Subject: Re: A problem on TCP in High RTT Environment. Date: Sun, 10 Aug 2014 04:46:29 +0100 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Cc: Michael Tuexen , Bill Yuan , freebsd-net@freebsd.org X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 10 Aug 2014 03:46:47 -0000 ----- Original Message ----- From: "John-Mark Gurney" > Niu Zhixiong wrote this message on Sun, Aug 10, 2014 at 10:50 +0800: >> I am sorry that I upload a WRONG SCTP capture. But, the throughput is >> same. >> SCTP is double than TCP, about 18Mbps. >> ??? >> sctp_2.pcapng.gz >> >> ??? > > Ok, the owin graph is very interesting... We do have a full 2MB > window > on the receiver side, but for some reason, we only ever have just > under > 6k outstanding on the connection... > > So, it looks like we send for a short period of time, and then stop > sending... Do you have LRO enabled? I think it might be related to: > https://svnweb.freebsd.org/changeset/base/r256920 > > As I'm seeing >100ms gaps where the sender doesn't send any data, and > as soon as more than one ack comes in, the next segment goes out... > If > we only receive a single ack, then we wait for a timeout before > sending > the next segment.. > > Can you try to disable LRO on the receiving host? > > ifconfig -lro > > And see if that helps... If it does... Applying the patch, or > compiling > a more recent kernel from stable/10 that is after r257367 as that is > was > the date that the change was merged... r257367 was in 10.0-RELEASE