In article <[EMAIL PROTECTED]>, John Pettitt <[EMAIL PROTECTED]> writes >I'll second the soekris box - my box time.no-such-agency.net is a 4801 >running FreeBSD with a GPS18LVC. You can expect offsets in the +/- >5us range except when the box is stressed - the standard xtal in the box >is not temperature compensated so offsets will spike to as much as 250us >when the system does something compute intensive. If you don't need the >HD consider the 4501 as it has the ability to timestamp a PPS using >internal counters rather than the DCD kludge. - Again see phk's >excellent work on the subject including the code in FreeBSD to support >PPS on a 4501.
So you'd recommend a 4501, with FreeBSD in Compact Flash? I wanted to use CF anyway, since a box running 24/7 is not the best environment in which to have moving parts. The box will have no more that NTP and MRTG on it. Thanks for the accuracy estimate. > >Regarding DSL - I now have three stratum one servers here: a GPS18LVC, a >TrueTime NTS100 and TrueTime GPS XL-DC (it is addictive isn't it) - my >ISP just installed a GPS18LVC based server one hop (on gig-e) from my >DSL concentrator so I can get a very clear picture of the error >introduced by my DSL asymmetry. For my line (6000 down 608 up >backhauled over ATM) it's 1.5ms. In a perfect world NTP would allow a >fudge offset to be applied to subnets (in my case 1.5ms on the default >and 0.0 on the local LAN) which would factor out the know DSL error - >alas it doesn't do that right now. My ADSL is 2272 down/256 up, so I'd likely be seeing bigger asymmetry. Thanks, -- Geoff Powell _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
