From owner-freebsd-hackers Wed May 19 4: 2:56 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from fep1-orange.clear.net.nz (fep1-orange.clear.net.nz [203.97.32.1]) by hub.freebsd.org (Postfix) with ESMTP id 573E115453 for ; Wed, 19 May 1999 04:02:50 -0700 (PDT) (envelope-from jabley@buddha.clear.net.nz) Received: from buddha.clear.net.nz (buddha.clear.net.nz [192.168.24.106]) by fep1-orange.clear.net.nz (1.5/1.13) with ESMTP id XAA29849; Wed, 19 May 1999 23:02:48 +1200 (NZST) Received: (from jabley@localhost) by buddha.clear.net.nz (8.9.3/8.9.2) id XAA00581; Wed, 19 May 1999 23:02:44 +1200 (NZST) (envelope-from jabley) Date: Wed, 19 May 1999 23:02:44 +1200 From: Joe Abley To: Ladavac Marino Cc: Matthew Dillon , Joe McGuckin , hackers@FreeBSD.ORG, jabley@clear.co.nz Subject: Re: GPS receivers for xntpd (off-topic) Message-ID: <19990519230244.B133@clear.co.nz> References: <55586E7391ACD211B9730000C1100276179609@r-lmh-wi-100.corpnet.at> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.4i In-Reply-To: <55586E7391ACD211B9730000C1100276179609@r-lmh-wi-100.corpnet.at>; from Ladavac Marino on Wed, May 19, 1999 at 12:30:38PM +0200 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wed, May 19, 1999 at 12:30:38PM +0200, Ladavac Marino wrote: > [ML] Back to my olden telco days some 10+ years ago when SDH > was on paper only and ATM was on benches, this sounds like 2MHz H1* > clock synchronized to GPS. Since transmission does not need the time of > day info (at least it did not need it last time I had any contact with > it, ages ago), I don't think there is any time of day info in that clock > output which would make this particular GPS receiver useless for NTP > purposes. Unless, of course, there is another output on the receiver > which provides the time of day info as well. I had kind of assumed the same thing; however, I was hoping I could T off a feed from the GPS antenna to a new receiver with different outputs, which we would purchase to provide time-of-day synchronisation rather than 1/2000 second synchronisation. It seems that there are a number of receivers that will do the job, but people are mentioning async interfaces and ethernet interfaces, and I am confused :) More random off-topic questions: a GPS synchronised clock is stratum-2, right? The caesium clock which provides synchronisation to the GPS is stratum-1? Sorry for the wasted bandwidth. Feel free to divert me privately to a FAQ on this, rather than cluttering up -hackers (I looked but couldn't find one). > [ML] * I think it's H1 I'm talking about: 30+2 channels of > 64kbps. European equivalent of T1. Approx. 2MHz. E1. Joe To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message