Survey of NTP surveys - NTP

This is a discussion on Survey of NTP surveys - NTP ; The little I know about NTP surveys, in chronological order: 1989, Mills, http://www.eecis.udel.edu/~mills/database/papers/ccr.ps 1994, James Guyton, I only know of this because it is referenced in Minar below. 1997, Mills, http://www.eecis.udel.edu/~mills/dat...ers/survey5.ps 1999, Nelson Minar, http://alumni.media.mit.edu/~nelson/.../ntp-survey99/ 2005, Cristina Duarte Murta and ...

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Thread: Survey of NTP surveys

  1. Survey of NTP surveys

    The little I know about NTP surveys, in chronological order:

    1989, Mills, http://www.eecis.udel.edu/~mills/database/papers/ccr.ps

    1994, James Guyton, I only know of this because it is referenced in
    Minar below.

    1997, Mills,
    http://www.eecis.udel.edu/~mills/dat...ers/survey5.ps

    1999, Nelson Minar,
    http://alumni.media.mit.edu/~nelson/.../ntp-survey99/

    2005, Cristina Duarte Murta and Pedro R. Torres Junior,
    http://ntpsurvey.arauc.br/

    Any other URL's I should know of?

    Interesting numbers for time evolution of count of stratum-1's:

    1994: 66
    1997: 220
    1999: 957
    2005: 533

    Minar (1999) reveals that vast majority (657 of the 957) of claimed
    Stratum 1's that he counted are in fact LCL (not obviously tied to a
    refclock). The decrease between 1999 and 2005 numbers may reflect not a
    decrease in Stratum 1's that are locked, but in fact a decrease in
    misconfigured NTP hosts. (Minar identifies a specific Red Hat
    distribution responsible for many of the misconfigurations, and I
    suspect that few of these are still alive.)

    I would be most interested if the 2005 survey (which the authors say is
    in the publication process) reveals some details about the stratum-1's
    and their diversity of refclocks. At the time of Minar's 1999 survey
    GPS was far and away most common, and I suspect that diversity of
    refclocks has degraded even more since then.

    Tim.


  2. Re: Survey of NTP surveys

    Tim,

    not all Stratum 1 administrators allow "strangers" to do:

    ntpdc -n -c sysinfo -c peers -c monlist

    on thier machines.

    So, I suspect the information about refclocks are not enough accurate
    to make a conclusion. I have three Stratum 1 servers available to the
    public ONLY for time synchronization.


  3. Re: Survey of NTP surveys

    shoppa@trailing-edge.com writes:

    >Any other URL's I should know of?


    Several people did various NTP observations around the leap second
    at the end of 2005. I guess this has a different emphasis to a
    general survey, but does represent measurements of the NTP network.
    My observations of the leap second are recorded at:

    http://www.maths.tcd.ie/~dwmalone/time/leap2005.html

    and include some NTP stuff. I also have some links to what other
    people recorded, though the list is not exhaustive.

    David.

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