From owner-freebsd-net Wed Jan 24 17:33:37 2001 Delivered-To: freebsd-net@freebsd.org Received: from khavrinen.lcs.mit.edu (khavrinen.lcs.mit.edu [18.24.4.193]) by hub.freebsd.org (Postfix) with ESMTP id 6816637B401 for ; Wed, 24 Jan 2001 17:33:20 -0800 (PST) Received: (from wollman@localhost) by khavrinen.lcs.mit.edu (8.9.3/8.9.3) id UAA73836; Wed, 24 Jan 2001 20:33:14 -0500 (EST) (envelope-from wollman) Date: Wed, 24 Jan 2001 20:33:14 -0500 (EST) From: Garrett Wollman Message-Id: <200101250133.UAA73836@khavrinen.lcs.mit.edu> To: Tatsuhiko Terai Cc: freebsd-net@freebsd.org Subject: Re: estimation of RTT,RTO from tcpcb parameter In-Reply-To: <3A6F72E71D6.7B48GENUINE@ma4.justnet.ne.jp> References: <3A6F67132EE.7B47GENUINE@ma4.justnet.ne.jp> <200101250009.TAA73303@khavrinen.lcs.mit.edu> <3A6F72E71D6.7B48GENUINE@ma4.justnet.ne.jp> Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org < said: > 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)? The system timer ticks at a rate of 100 Hz on all IA32 processors. (I believe on Alphas it ticks at 1024 Hz but I may be imagining it.) Thus, the period is either 10 ms or 0.98 ms. In historic versions of FreeBSD, most TCP timers ticked at 2 Hz while the others ticked at 5 Hz. This was changed in advance of FreeBSD 4.0. -GAWollman To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message