Author Topic: Internet Time Service protocol  (Read 6531 times)

Offline Richard

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Internet Time Service protocol
« on: March 28, 2008, 06:09:26 AM »
Hi.  I'm back to thinking about time and putting information about the time zone into the parameter block.  In the process, I stumbled across the following information about the NIST Internet Time Service (ITS) http://tf.nist.gov/service/its.htm.  They will eventually no longer support the time protocol used in the uTasker code, Time Protocol (RFC-868), which uses port 37.  They say it is used by only about 1% of their users, and they want everyone to move to Network Time Protocol (RFC-1305), which uses port 123.

Quote
Starting on 14 April 2007 the server time.nist.gov will no longer respond to requests for time in the TIME format (as defined in RFC-868). These requests are generated by a number of different programs including DATE, RDATE, and other programs that connect to the time server using tcp or udp port 37. All of the other NIST servers (except for time-nw.nist.gov) will continue to respond to requests to either tcp or udp port 37 for time in the format specified in RFC-868.

However, this format has poor error-handling capabilities in general, and many of the client programs that use this format are poorly written and may not handle network errors properly. Therefore users are strongly encouraged to switch to the Network Time Protocol (NTP), which is more robust and provides greater accuracy. We eventually intend to phase out support for the TIME format on all servers.

Please send questions or comments regarding this issue to Judah Levine: jlevine@boulder.nist.gov

For my purposes, the older, RFC-868 protocol is good enough, but I'd hate to see an application fail in the field because NIST decides to pull the plug on the service, especially since they've given warning well in advance.  So, eventually [but it could be years, who knows?] we'll all be forced to use the new protocol, or at least the simplified version of NTP, suitable for most uses, specified in RFC-4330.

Has anyone worked with this?  Has anyone written a modified version of the uTasker TIME client that makes use of the newer protocol that he would be willing to share?  Is there a simple reference version available on the Internet?  All the sample code provided by NIST uses older protocols.  All the other reference code I can find spreads the details over dozens of files -- and it can't be that hard.

I shouldn't let this stop me from figuring out how to put time zone information into the parameter block, with a way for the user to update it for summer time or a change in location (probably via a web page).

Cheers,
    Richard

Offline mark

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Re: Internet Time Service protocol
« Reply #1 on: March 28, 2008, 09:05:14 PM »
Hi Richard

I did look at this protocol recently and noted that there was a simplified method when highest synchronisation accuracy is not required. But i didn't look in that much detail.

Your point about a replacement for the (very) simply time server is valid. Let me know if you do any work to implement it and I may take a closer look againsoon.

Regards

Mark