From owner-freebsd-net Wed Jan 24 7:56:49 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 2EF2A37B401 for ; Wed, 24 Jan 2001 07:56:32 -0800 (PST) Received: (qmail 21980 invoked from network); Thu, 25 Jan 2001 00:56:29 +0900 Received: (ofmipd 133.1.17.145); Thu, 25 Jan 2001 00:56:29 +0900 Date: Thu, 25 Jan 2001 00:57:55 +0900 Message-Id: <3A6EFB83208.3FA9GENUINE@ma4.justnet.ne.jp> From: Tatsuhiko Terai To: freebsd-net@FreeBSD.ORG Cc: genuine@ma4.justnet.ne.jp Subject: estimation of RTT,RTO from tcpcb parameter 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 (This mail is the multi-post to freebsd-net-jp. I'm sorry for the person who receives the duplicate mail.) I have a question about the estimation RTT, RTO using the information in tcpcb (t_srtt, t_rttvar). I'm trying to estimate network status at the kernel level using tcpcb information, obtain the estimation of RTT, RTO. I know that UNIX is not allowed floating point calculation in the kernel, so RTT estimator is implemented as using int. However, I don't know the method of calculation of the now RTT, RTO using t_srtt, t_rttvar in kernel tcpcb and so on. I hope that it is useful that I obtain the [ms]-order RTT,RTO >from that parameter. If there is an information about this, or anyone know the way of calculation, please teach me. Thanks. Tatsuhiko. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message