Rob <[email protected]> wrote in news:[email protected]:
> nemo_outis <[email protected]> wrote: >> True, one can chase any number of will-o-the-wisps such as the causes >> of the network latency and asymmetry, but that is not the central >> problem posed by the OP. > > But it is! > >> In short, Unruh may be boring in his reiteration of his simple GPS >> solution, but that is because it works for a very wide range of >> problems - including this one! > > No, not at all. The poster wants to be within 1ms of his chosen > reference clock, and syncing to GPS is bringing nothing towards that. First, the OP isn't going to synchronize anything with anything to 1 ms given the high and irregular latencies on his network. In short, he doesn't have a time problem, he has a network problem. Second, it is true that the OP presented his problem as merely keeping Lamport time linked to an arbitrary shipboard server (ntpgmtaceb) of unknown stability and accuracy - a task which is presently unachievable and may ultimately be of limited utility. But, of course, it's up to the OP to decide if such a makeshift approach encapsulating what may be charitably called ntp "worst practices" is "good enough." However, it would be irresponsible for Unruh and others here not to point out that a much better timekeeping solution is readily available - a solution which is technically easy to implement. Unruh has rightly pointed out that installing a GPS sensor would be clearly better than the current ludicrous 18th century policy of setting the master clock at voyage outset and then earnestly hoping that subsequent drift (or other timekeeping irregularities) is not "too bad." That the OP may not be able or willing to implement such a straightforward solution (whether from his lack of stroke or his superiors' indifference) does not invalidate the suggestion. Moreover, that you find Unruh's pointing out the elephant in the room tiresome only indicts your judgment, not his. Regards, _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
