From owner-freebsd-net Wed Jan 24 16:26:13 2001 Delivered-To: freebsd-net@freebsd.org Received: from ma4.justnet.ne.jp (ma4p.justnet.ne.jp [133.130.3.12]) by hub.freebsd.org (Postfix) with SMTP id C6A3237B400 for ; Wed, 24 Jan 2001 16:25:56 -0800 (PST) Received: (qmail 6721 invoked from network); Thu, 25 Jan 2001 09:25:52 +0900 Received: (ofmipd 133.1.17.145); Thu, 25 Jan 2001 09:25:52 +0900 Date: Thu, 25 Jan 2001 09:27:19 +0900 Message-Id: <3A6F72E71D6.7B48GENUINE@ma4.justnet.ne.jp> From: Tatsuhiko Terai To: Garrett Wollman Cc: freebsd-net@freebsd.org Subject: Re: estimation of RTT,RTO from tcpcb parameter In-Reply-To: <200101250009.TAA73303@khavrinen.lcs.mit.edu> References: <3A6F67132EE.7B47GENUINE@ma4.justnet.ne.jp> <200101250009.TAA73303@khavrinen.lcs.mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver 1.26.02 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Thanks for your advise. > No. Please take a look at W. Richard Stevens' _TCP/IP Illustrated_ > series, particularly volume 2. > I'll try. > Nothing inside the kernel is measured in milliseconds. TCP parameters > are measured in timer ticks, the length of which depends on which > version of FreeBSD you are running and (potentially) on what hardware > platform. By the way, my running machine is P-III 1GHz with i820 chip and FreeBSD-4.0-RELEASE. Is the length of time tick for this plathome invert of 1GHz? (1/10^-9 [s])? or 10 [ms] (I think it is the time ticks for FreeBSD)? RTT = (tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT) shows sometimes rapidly increase to 40 between ti0 gigabit link. I think 40 * 10 [ms] is too longer for rtt, so I confused.. If there is some information, would you please like toteach ? Thanks- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message