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Calculating response times RRS feed

  • Question

  • Using Network Monitor 3.3 (3.4 of the parsers):

    I'm trying to document a latency issue on the network. But NetMon is not providing the data. For example:

    5  18.359375  10.10.10.1   10.10.8.1  ICMP:Echo Request Message,
    6  18.359375  10.10.8.1  10.10.10.1   ICMP:Echo Reply Message,

    The "time offset" of 18.359375 is the same for both request and reply, yet the ping that created this trace reported a 7ms response.

    DNS querys normally take about 100ms yet I get this nonsense:

    27  177.265625  10.10.10.1  10.10.8.1  DNS:QueryId = 0x0, QUERY (Standard query), Query
    28  177.265625  10.10.8.1  10.10.10.1  DNS:QueryId = 0x0, QUERY (Standard query), Response - Success

    A DNS query certainly does not take 0ms! 

    Every now and again Netmon decides to record a slight difference in the DNS query/response time: It is always 0.015625!

    Is there something very wrong with NetMon?

    Thanks

    Paul
    Friday, January 29, 2010 3:23 PM

Answers

  • Hi Paul,

    Sorry for the inconvenience.  Unfortunately, Network Monitor 3.3 only has a resolution of about 15ms.  We have addressed this in the next version though.

    As for your DNS query, I'm not sure why it still shows as instantaneous, unless maybe it was just retrieving from your local cache?
    Michael Hawker | Program Manager | Network Monitor
    • Marked as answer by Frogbit Saturday, January 30, 2010 8:01 AM
    Friday, January 29, 2010 5:49 PM

All replies

  • Hi Paul,

    Sorry for the inconvenience.  Unfortunately, Network Monitor 3.3 only has a resolution of about 15ms.  We have addressed this in the next version though.

    As for your DNS query, I'm not sure why it still shows as instantaneous, unless maybe it was just retrieving from your local cache?
    Michael Hawker | Program Manager | Network Monitor
    • Marked as answer by Frogbit Saturday, January 30, 2010 8:01 AM
    Friday, January 29, 2010 5:49 PM
  • Thanks Michael,

    15ms resolution certainly explains the "instantaneous" pings and the odd DNS round-trips too; I'm sure the DNS query tool I'm using (IPSentry) suggests >30ms at times, but this tool has proved to be the source of some pretty wild results!

    I think I'll trust NetMon and its 15ms resolution and start treating this other tool with suspicion.

    Paul
    Saturday, January 30, 2010 8:01 AM
  • Hi Paul,

    Sorry for the inconvenience.  Unfortunately, Network Monitor 3.3 only has a resolution of about 15ms.  We have addressed this in the next version though.

    As for your DNS query, I'm not sure why it still shows as instantaneous, unless maybe it was just retrieving from your local cache?
    Michael Hawker | Program Manager | Network Monitor

    Though the problem cannot be solved, Finally got my question answered.
    Monday, August 23, 2010 11:55 PM
  • Hi Peter,

    But the problem is solved!  Network Monitor 3.4 has already been released in June.  You can download it here: http://go.microsoft.com/fwlink/?LinkID=103158.

    It has much greater timer resolution to about 100 nanoseconds.


    Michael Hawker | Program Manager | Network Monitor
    Tuesday, August 24, 2010 6:05 PM