Reply from Judah below: /tvb ----- Original Message ----- From: Levine, Judah Dr. (Fed) Sent: Tuesday, March 20, 2018 6:49 AM Subject: Re: [Non-DoD Source] Re: [LEAPSECS] current / future state of UT1 access?
Dear colleagues, The current UT1 time server has 550 users and is receiving about 10 requests per second. These are both extremely small numbers compared to my other servers. I cannot explain Rob Seaman’s experience. I routinely monitor all of the servers and do not see this problem. I have not received any other complaints about the service. In spite of all of this, there is no difficulty in adding a second UT1 time server at another location. From my perspective, the easiest solution would be to add the second UT1 server at WWV. The IP address of the new server would be 132.163.97.x. There are already 4 servers at this site with addresses 132.163.97.1-4, and I encourage the community to verify that these servers are available from a network perspective. Judah Levine On: 19 March 2018 11:33, "Matsakis, Demetrios N CIV NAVOBSY, N3TS" <[email protected]> wrote: FYI. If you wish me to relay a message to this group, I'd be willing to. ________________________________ From: LEAPSECS [[email protected]] on behalf of Rob Seaman [[email protected]] Sent: Monday, March 19, 2018 1:30 PM To: [email protected] Subject: [Non-DoD Source] Re: [LEAPSECS] current / future state of UT1 access? I appreciate the feedback from everybody on the UT1 NTP issue. I have yet to successfully connect from campus and possibly Martin's comment applies since there are a lot of telescopes and astronomers here working for several observatories. Somebody else on this end may be bogarting the NIST UT1 (though we get through fine to their UTC servers). The issue has come up now since a colleague asked about best practices for access to UT1. In the mean time he's implemented yet another internet retrieval of Bulletin A. Perhaps it needs to be stressed again, astronomers require access to both Universal Time and Atomic Time. The NIST UT1 server is not currently useful for our purposes. Perhaps a UT1 pool will make sense at some point? If the NIST servers are all loaded "sky high", is there any plan to mitigate this through data center / networking best practices? We have seen their other servers' reach faltering at this end, too. Thanks! Rob -- On 3/19/18 7:43 AM, Martin Burnicki wrote: Please note you need to take care if you have several nodes behind a NAT router that poll the same server. From the server's point of view it looks like all the requests from the nodes behind the router seem to come from the same (public) IP address, so a particular node on the NAT subnet may receive even less replies. On 3/19/18 9:48 AM, Poul-Henning Kamp wrote: You can simply test this if you run "ntpdate -d -p1 <hostname>" repeatedly. When I try this for a NIST server here from Germany I only receive a reply occasionally, and in most cases I don't. Last I heard about it, the packet load on the NIST servers were sky high so I am not the least surprised... _______________________________________________ LEAPSECS mailing list [email protected] https://pairlist6.pair.net/mailman/listinfo/leapsecs
