Date: Wed, 19 May 1999 12:30:38 +0200 From: Ladavac Marino <mladavac@metropolitan.at> To: 'Joe Abley' <jabley@clear.co.nz>, Matthew Dillon <dillon@apollo.backplane.com> Cc: Joe McGuckin <joe@monk.via.net>, hackers@FreeBSD.ORG Subject: RE: GPS receivers for xntpd (off-topic) Message-ID: <55586E7391ACD211B9730000C1100276179609@r-lmh-wi-100.corpnet.at>
next in thread | raw e-mail | index | archive | help
> -----Original Message----- > From: Joe Abley [SMTP:jabley@clear.co.nz] > Sent: Wednesday, May 19, 1999 12:09 PM > To: Matthew Dillon > Cc: Joe McGuckin; hackers@FreeBSD.ORG; jabley@clear.co.nz > Subject: GPS receivers for xntpd (off-topic) > > On Tue, May 18, 1999 at 11:02:38PM -0700, Matthew Dillon wrote: > > [various GPS chat] > > I have been meaning to do some research on this kind of stuff for a > while. > We have GPS receivers in the machine room that supply clock for some > of > the transmission network, but when I ask the telco guys about the > output > of these receivers they just frown confusedly and say "it's a 2 meg > clock". > I haven't mentioned NTP, because I can't be bothered to spell it for > them :) > [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. [ML] * I think it's H1 I'm talking about: 30+2 channels of 64kbps. European equivalent of T1. Approx. 2MHz. [ML] /Marino > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?55586E7391ACD211B9730000C1100276179609>