Comparison between ntpd and TSCclock - NTP

This is a discussion on Comparison between ntpd and TSCclock - NTP ; Developers at the University of Melbourne have produced a time-sync client called "TSCclock" which exchanges standard NTP packets with a NTP server. They assert that TSCclock, which runs on FreeBSD and at least two flavors of Linux (Ubuntu and Fedora), ...

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  1. Comparison between ntpd and TSCclock

    Developers at the University of Melbourne have produced a time-sync
    client called "TSCclock" which exchanges standard NTP packets with a
    NTP server. They assert that TSCclock, which runs on FreeBSD and at
    least two flavors of Linux (Ubuntu and Fedora), provides substantially
    better synchronization than ntpd both on a LAN and over the Internet.

    The following info is some of what is available:

    1. The TSCclock page at the University of Melbourne:
    http://www.cubinlab.ee.unimelb.edu.au/tscclock/

    2. A paper titled "Ten Microseconds Over LAN, for Free", originally
    presented at the 2007 International IEEE Symposium on Precision Clock
    Synchronization for Measurement, Control and Communication. This is
    available at
    http://www.cubinlab.ee.unimelb.edu.a...S07_camera.pdf
    It includes a general description of their approach and results for
    both ntpd and TSCclock obtained in their testbed.

    3. A one-hour Google Tech Talk: http://www.youtube.com/watch?v=o3nXgeh7v_U

    All of the info on TSCclock that I have run across has originated with
    the group at the University of Melbourne. Does anyone know of an
    independent comparison between ntpd and TSCclock?

    Thanks,
    Gene

  2. Re: Comparison between ntpd and TSCclock

    Gene,

    I've seen and reviewed the paper; however, reviews are private to the
    authors. Someone else should take a close look at what they are actually
    measuring and assess the dynmaics of the discipline loop.

    Dave

    eugenemil@sbcglobal.net wrote:
    > Developers at the University of Melbourne have produced a time-sync
    > client called "TSCclock" which exchanges standard NTP packets with a
    > NTP server. They assert that TSCclock, which runs on FreeBSD and at
    > least two flavors of Linux (Ubuntu and Fedora), provides substantially
    > better synchronization than ntpd both on a LAN and over the Internet.
    >
    > The following info is some of what is available:
    >
    > 1. The TSCclock page at the University of Melbourne:
    > http://www.cubinlab.ee.unimelb.edu.au/tscclock/
    >
    > 2. A paper titled "Ten Microseconds Over LAN, for Free", originally
    > presented at the 2007 International IEEE Symposium on Precision Clock
    > Synchronization for Measurement, Control and Communication. This is
    > available at
    > http://www.cubinlab.ee.unimelb.edu.a...S07_camera.pdf
    > It includes a general description of their approach and results for
    > both ntpd and TSCclock obtained in their testbed.
    >
    > 3. A one-hour Google Tech Talk: http://www.youtube.com/watch?v=o3nXgeh7v_U
    >
    > All of the info on TSCclock that I have run across has originated with
    > the group at the University of Melbourne. Does anyone know of an
    > independent comparison between ntpd and TSCclock?
    >
    > Thanks,
    > Gene


  3. Re: Comparison between ntpd and TSCclock

    Are they planning an implementation for Windoze anytime soon?

    Brian


    wrote in message
    news:1cd841cf-4671-4fd3-a4c3-12d8a505e685@34g2000hsf.googlegroups.com...
    > Developers at the University of Melbourne have produced a time-sync
    > client called "TSCclock" which exchanges standard NTP packets with a
    > NTP server. They assert that TSCclock, which runs on FreeBSD and at
    > least two flavors of Linux (Ubuntu and Fedora), provides substantially
    > better synchronization than ntpd both on a LAN and over the Internet.




  4. Re: Comparison between ntpd and TSCclock

    I was at the conference and did talk to the presenter but I don't
    remember discussions about enhanced performance over Internet (capital
    I). My recollection is that they were running sync over a lan and
    achieving performance sub 100usec which is readily achievable with most
    software solutions. They ran on a constrained network, leveraged local
    counter stability to set sampling interval, clamped poll interval to low
    values (16-256 I think). This is good stuff but not new. Looking at
    the last figure does show a larger path with good error values for the
    tsclock approach but that is only the first step. I'd be interested in
    data as to delay variation over the test, effects of initial offsets in
    phase and frequency, analysis of servo for loop bandwidth, etc.

    When I asked about some joint testing or contribution to ietf, there was
    no interest at the time. Perhaps that has changed.

    Greg Dowd
    gdowd at symmetricom dot com (antispam format)
    Symmetricom, Inc.
    www.symmetricom.com
    "Everything should be made as simple as possible, but no simpler" Albert
    Einstein


    > -----Original Message-----
    > From: questions-bounces+gdowd=symmetricom.com@lists.ntp.org
    > [mailto:questions-bounces+gdowd=symmetricom.com@lists.ntp.org]
    > On Behalf Of eugenemil@sbcglobal.net
    > Sent: Tuesday, May 13, 2008 6:22 PM
    > To: questions@lists.ntp.org
    > Subject: [ntp:questions] Comparison between ntpd and TSCclock
    >
    > Developers at the University of Melbourne have produced a
    > time-sync client called "TSCclock" which exchanges standard
    > NTP packets with a NTP server. They assert that TSCclock,
    > which runs on FreeBSD and at least two flavors of Linux
    > (Ubuntu and Fedora), provides substantially better
    > synchronization than ntpd both on a LAN and over the Internet.
    >
    > The following info is some of what is available:
    >
    > 1. The TSCclock page at the University of Melbourne:
    > http://www.cubinlab.ee.unimelb.edu.au/tscclock/
    >
    > 2. A paper titled "Ten Microseconds Over LAN, for Free",
    > originally presented at the 2007 International IEEE Symposium
    > on Precision Clock Synchronization for Measurement, Control
    > and Communication. This is available at
    > http://www.cubinlab.ee.unimelb.edu.a...blications/ISP

    CS07_camera.pdf
    > It includes a general description of their approach and
    > results for both ntpd and TSCclock obtained in their testbed.
    >
    > 3. A one-hour Google Tech Talk:
    > http://www.youtube.com/watch?v=o3nXgeh7v_U
    >
    > All of the info on TSCclock that I have run across has
    > originated with the group at the University of Melbourne.
    > Does anyone know of an independent comparison between ntpd
    > and TSCclock?
    >
    > Thanks,
    > Gene
    >
    > _______________________________________________
    > questions mailing list
    > questions@lists.ntp.org
    > https://lists.ntp.org/mailman/listinfo/questions
    >


  5. Re: Comparison between ntpd and TSCclock

    eugenemil@sbcglobal.net writes:

    >Developers at the University of Melbourne have produced a time-sync
    >client called "TSCclock" which exchanges standard NTP packets with a
    >NTP server. They assert that TSCclock, which runs on FreeBSD and at
    >least two flavors of Linux (Ubuntu and Fedora), provides substantially
    >better synchronization than ntpd both on a LAN and over the Internet.


    >The following info is some of what is available:


    >1. The TSCclock page at the University of Melbourne:
    >http://www.cubinlab.ee.unimelb.edu.au/tscclock/


    >2. A paper titled "Ten Microseconds Over LAN, for Free", originally
    >presented at the 2007 International IEEE Symposium on Precision Clock
    >Synchronization for Measurement, Control and Communication. This is
    >available at
    >http://www.cubinlab.ee.unimelb.edu.a...S07_camera.pdf
    >It includes a general description of their approach and results for
    >both ntpd and TSCclock obtained in their testbed.


    The paper suffers from talking nonesense. NTP is certainly better than 1ms
    on a lan, and their data shows that the jitter is around .1-.2 ms.
    Exagerating the difference does not do them any favours.

    Note that chrony ( a 10 year old system) already gives 10usec for free on
    the lan.

    Futhermore their poll interval for their system is much higher than that of
    ntp. I get about .05 msec jitter for ntp on a lan, at least on my testbed.
    The ideas are interesting ( certainly their attempt to compensate for
    network jitter, their chief difference from ntp, is far superior to the
    clock filter approach of ntp, and I suspect superiour to the "weighting"
    approach of chrony ( the data is weighted by the inverse of the delay)




    >3. A one-hour Google Tech Talk: http://www.youtube.com/watch?v=o3nXgeh7v_U


    >All of the info on TSCclock that I have run across has originated with
    >the group at the University of Melbourne. Does anyone know of an
    >independent comparison between ntpd and TSCclock?


    >Thanks,
    >Gene


  6. Re: Comparison between ntpd and TSCclock

    "David L. Mills" writes:

    >Gene,


    >I've seen and reviewed the paper; however, reviews are private to the


    Their paper is public. It is posted on the web.

    >authors. Someone else should take a close look at what they are actually
    >measuring and assess the dynmaics of the discipline loop.


    Did you do so? If so, your analysis would be of interest. And I cannot see
    why the analysis of a public paper should be kept private.


    >Dave


    >eugenemil@sbcglobal.net wrote:
    >> Developers at the University of Melbourne have produced a time-sync
    >> client called "TSCclock" which exchanges standard NTP packets with a
    >> NTP server. They assert that TSCclock, which runs on FreeBSD and at
    >> least two flavors of Linux (Ubuntu and Fedora), provides substantially
    >> better synchronization than ntpd both on a LAN and over the Internet.
    >>
    >> The following info is some of what is available:
    >>
    >> 1. The TSCclock page at the University of Melbourne:
    >> http://www.cubinlab.ee.unimelb.edu.au/tscclock/
    >>
    >> 2. A paper titled "Ten Microseconds Over LAN, for Free", originally
    >> presented at the 2007 International IEEE Symposium on Precision Clock
    >> Synchronization for Measurement, Control and Communication. This is
    >> available at
    >> http://www.cubinlab.ee.unimelb.edu.a...S07_camera.pdf
    >> It includes a general description of their approach and results for
    >> both ntpd and TSCclock obtained in their testbed.
    >>
    >> 3. A one-hour Google Tech Talk: http://www.youtube.com/watch?v=o3nXgeh7v_U
    >>
    >> All of the info on TSCclock that I have run across has originated with
    >> the group at the University of Melbourne. Does anyone know of an
    >> independent comparison between ntpd and TSCclock?
    >>
    >> Thanks,
    >> Gene


  7. Re: Comparison between ntpd and TSCclock

    "Brian Garrett" writes:

    >Are they planning an implementation for Windoze anytime soon?


    HOw would you get good results when you have no means of controlling the
    clock except stepping?



    >Brian



    > wrote in message
    >news:1cd841cf-4671-4fd3-a4c3-12d8a505e685@34g2000hsf.googlegroups.com...
    >> Developers at the University of Melbourne have produced a time-sync
    >> client called "TSCclock" which exchanges standard NTP packets with a
    >> NTP server. They assert that TSCclock, which runs on FreeBSD and at
    >> least two flavors of Linux (Ubuntu and Fedora), provides substantially
    >> better synchronization than ntpd both on a LAN and over the Internet.




  8. Re: Comparison between ntpd and TSCclock

    Unruh wrote:
    > "Brian Garrett" writes:
    >
    >> Are they planning an implementation for Windoze anytime soon?

    >
    > HOw would you get good results when you have no means of controlling
    > the clock except stepping?


    Are you sure? Windows provides a rate adjustment, as well as stepping.

    David



  9. Re: Comparison between ntpd and TSCclock

    Bill,

    Who, me? Paper reviewers are supposed to anonymous. Let's just say I
    agree with your assessment.

    I've seen a number of papers like this; some I have reviewed. They are
    written by folks with computer science backgrounds and are not well
    trained in physics and engineering principles and even less in the
    physical properties of real oscillators. You (and others) might not like
    the NTP mitigation and discipline algorithms, but each one is based on
    thorough analysis with respect to sound physics and engineering
    principles as confirmed by measurement over a wide body of scenarios.

    Unruh wrote:

    > "David L. Mills" writes:
    >
    >
    >>Gene,

    >
    >
    >>I've seen and reviewed the paper; however, reviews are private to the

    >
    >
    > Their paper is public. It is posted on the web.
    >
    >
    >>authors. Someone else should take a close look at what they are actually
    >>measuring and assess the dynmaics of the discipline loop.

    >
    >
    > Did you do so? If so, your analysis would be of interest. And I cannot see
    > why the analysis of a public paper should be kept private.
    >
    >
    >
    >>Dave

    >
    >
    >>eugenemil@sbcglobal.net wrote:
    >>
    >>>Developers at the University of Melbourne have produced a time-sync
    >>>client called "TSCclock" which exchanges standard NTP packets with a
    >>>NTP server. They assert that TSCclock, which runs on FreeBSD and at
    >>>least two flavors of Linux (Ubuntu and Fedora), provides substantially
    >>>better synchronization than ntpd both on a LAN and over the Internet.
    >>>
    >>>The following info is some of what is available:
    >>>
    >>>1. The TSCclock page at the University of Melbourne:
    >>>http://www.cubinlab.ee.unimelb.edu.au/tscclock/
    >>>
    >>>2. A paper titled "Ten Microseconds Over LAN, for Free", originally
    >>>presented at the 2007 International IEEE Symposium on Precision Clock
    >>>Synchronization for Measurement, Control and Communication. This is
    >>>available at
    >>>http://www.cubinlab.ee.unimelb.edu.a...S07_camera.pdf
    >>>It includes a general description of their approach and results for
    >>>both ntpd and TSCclock obtained in their testbed.
    >>>
    >>>3. A one-hour Google Tech Talk: http://www.youtube.com/watch?v=o3nXgeh7v_U
    >>>
    >>>All of the info on TSCclock that I have run across has originated with
    >>>the group at the University of Melbourne. Does anyone know of an
    >>>independent comparison between ntpd and TSCclock?
    >>>
    >>>Thanks,
    >>>Gene


  10. Re: Comparison between ntpd and TSCclock

    "David L. Mills" writes:

    >Bill,


    >Who, me? Paper reviewers are supposed to anonymous. Let's just say I
    >agree with your assessment.


    Ah. OK. the anonymity is a consideration. Of course you could have come up
    with your objections to the paper entirely independently of that anonymous
    referee, and your agreement was just that any true thinkers would have
    agreed!


    >I've seen a number of papers like this; some I have reviewed. They are
    >written by folks with computer science backgrounds and are not well
    >trained in physics and engineering principles and even less in the
    >physical properties of real oscillators. You (and others) might not like
    >the NTP mitigation and discipline algorithms, but each one is based on
    >thorough analysis with respect to sound physics and engineering
    >principles as confirmed by measurement over a wide body of scenarios.


    >Unruh wrote:


    >> "David L. Mills" writes:
    >>
    >>
    >>>Gene,

    >>
    >>
    >>>I've seen and reviewed the paper; however, reviews are private to the

    >>
    >>
    >> Their paper is public. It is posted on the web.
    >>
    >>
    >>>authors. Someone else should take a close look at what they are actually
    >>>measuring and assess the dynmaics of the discipline loop.

    >>
    >>
    >> Did you do so? If so, your analysis would be of interest. And I cannot see
    >> why the analysis of a public paper should be kept private.
    >>
    >>
    >>
    >>>Dave

    >>
    >>
    >>>eugenemil@sbcglobal.net wrote:
    >>>
    >>>>Developers at the University of Melbourne have produced a time-sync
    >>>>client called "TSCclock" which exchanges standard NTP packets with a
    >>>>NTP server. They assert that TSCclock, which runs on FreeBSD and at
    >>>>least two flavors of Linux (Ubuntu and Fedora), provides substantially
    >>>>better synchronization than ntpd both on a LAN and over the Internet.
    >>>>
    >>>>The following info is some of what is available:
    >>>>
    >>>>1. The TSCclock page at the University of Melbourne:
    >>>>http://www.cubinlab.ee.unimelb.edu.au/tscclock/
    >>>>
    >>>>2. A paper titled "Ten Microseconds Over LAN, for Free", originally
    >>>>presented at the 2007 International IEEE Symposium on Precision Clock
    >>>>Synchronization for Measurement, Control and Communication. This is
    >>>>available at
    >>>>http://www.cubinlab.ee.unimelb.edu.a...S07_camera.pdf
    >>>>It includes a general description of their approach and results for
    >>>>both ntpd and TSCclock obtained in their testbed.
    >>>>
    >>>>3. A one-hour Google Tech Talk: http://www.youtube.com/watch?v=o3nXgeh7v_U
    >>>>
    >>>>All of the info on TSCclock that I have run across has originated with
    >>>>the group at the University of Melbourne. Does anyone know of an
    >>>>independent comparison between ntpd and TSCclock?
    >>>>
    >>>>Thanks,
    >>>>Gene


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