From owner-freebsd-net Fri Sep 20 18:52:55 2002 Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 24CE237B401 for ; Fri, 20 Sep 2002 18:52:54 -0700 (PDT) Received: from out1.mx.nwbl.wi.voyager.net (out1.mx.nwbl.wi.voyager.net [169.207.3.119]) by mx1.FreeBSD.org (Postfix) with ESMTP id A2FDF43E77 for ; Fri, 20 Sep 2002 18:52:53 -0700 (PDT) (envelope-from silby@silby.com) Received: from pop2.nwbl.wi.voyager.net (pop2.nwbl.wi.voyager.net [169.207.3.115]) by out1.mx.nwbl.wi.voyager.net (Postfix) with ESMTP id ADF5FE29D8; Fri, 20 Sep 2002 20:52:51 -0500 (CDT) Received: from [10.1.1.6] (d30.as29.nwbl0.wi.voyager.net [169.207.73.30]) by pop2.nwbl.wi.voyager.net (8.10.2/8.10.2) with ESMTP id g8L1qo124667; Fri, 20 Sep 2002 20:52:50 -0500 (CDT) Date: Fri, 20 Sep 2002 20:56:44 -0500 (CDT) From: Mike Silbersack To: Julian Elischer Cc: net@freebsd.org Subject: Re: Tcp question. In-Reply-To: Message-ID: <20020920204805.G6326-100000@patrocles.silby.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Fri, 20 Sep 2002, Julian Elischer wrote: > OK so I have 3 machines: > > > A------router--------B-------router--------C > > > if I send data from B to A I see 7MB/sec. > if I send data from B to C I see 700KB/sec > > tcpdump shows some odd behaviour in the slow link: > (tcpdump run from (B)) Could you repost with more of the timestamp intact? It's really hard to read as is. > 000221 C.ssh > B.916: . [tcp sum ok] ack 66194 win 24624 > nop,nop,timestamp 259781842 16260556> (DF) > (ttl 64, id 18252, len 52) > **why wait here**? > 003030 C.ssh > B.916: . [tcp sum ok] ack 68930 win 24624 > nop,nop,timestamp 259781842 16260556> (DF) > (ttl 64, id 18253, len 52) > 000279 C.ssh > B.916: P 3769:3813(44) ack 70298 win 24624 > nop,nop,timestamp 259781842 16260556> (DF) > (ttl 64, id 18254, len 96) Hm, the TCP stack doesn't look like it thinks that it's waiting... the timestamps don't seem to be incrementing. Of course, since I can't see the timestamp, I don't know what waiting means. :) Have you tried disabling delayed acks just to be doubly sure that the delayed ack code isn't causing the problem somehow? Also, is C really a FreeBSD box? I didn't think we used window sizes of 24K. Mike "Silby" Silbersack To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message