Ping times on a router during File Transfer (text version) - Connectivity

This is a discussion on Ping times on a router during File Transfer (text version) - Connectivity ; I am trying to troubleshoot a network issue with one of my clients and I'm finding a very strange occurrence. The customer is complaining of slow performance and application timeouts using a .NET application my company provides. During one function ...

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Thread: Ping times on a router during File Transfer (text version)

  1. Ping times on a router during File Transfer (text version)

    I am trying to troubleshoot a network issue with one of my clients and I'm
    finding a very strange occurrence.

    The customer is complaining of slow performance and application timeouts
    using a .NET application my company provides. During one function of the
    application, there is a lot of data transfer to the local workstation,
    cached on the local workstation, to fill in WinForms that user uses to
    change or save information to the remote database.

    During the initial data transfer, the customer reports that the application
    seems to stop responding. The WinForm is on the screen, but the mouse
    hourglasses and appears to be hung.

    When we try to do the same function on the same database from another
    location, it works, completing in more time than we would like it to
    complete, but it does finish. My developers are aware of this problem, but
    that does not stop us from looking at the apparent timeout issue.

    I've narrowed the problem to the ISP or the router. When we connect
    directly to the router, circumventing the enterprise firewall, the
    application acts the same way.

    To test the Internet issue, I remoted into a workstation and initiated an
    FTP session. I downloaded a 53MB file to the workstation and the ISP
    remoted into the router to monitor CPU usage, memory usage, and other
    parameters. The file downloaded in about 4 minutes with no interruptions
    that I could see. The ISP tech reported no unusual problems.

    I began the transfer again and pinged the router. My ping times were
    250-400ms. This is not a good amount of time to me, so I stopped the FTP
    and pinged the router again. This time, my ping times were 40-60ms.

    I did this back and forth, and I consistently got bad results during FTP and
    good results without the FTP.

    I had the ISP tech repeat my tests as I started and stopped the FTP. He
    pinged other locations and got similar results.

    The router is a Cisco 2600 series router. It services about 30 users in
    this customer's office.

    What can cause a router to delay a ping request for such a long period of
    time during a file transfer? I've repeated this experiment on other
    customers and did not receive these results; ping times remained the same
    during and outside of the FTP session.

    Please email me at rtocci@amsworld.com as well as responding to this post.
    Thank you for your help.

    --
    Richard Tocci
    College Station, TX

    All inbound and outbound e-mails are scanned for viruses. I probably did
    not send you a virus, but if you receive an e-mail with a virus from me, let
    me know.


    --
    Richard Tocci
    College Station, TX

    All inbound and outbound e-mails are scanned for viruses. I probably did
    not send you a virus, but if you receive an e-mail with a virus from me, let
    me know.



  2. Re: Ping times on a router during File Transfer (text version)

    In article <11272oq6j1hqm07@corp.supernews.com>, Richard Tocci wrote:

    >During the initial data transfer, the customer reports that the application
    >seems to stop responding. The WinForm is on the screen, but the mouse
    >hourglasses and appears to be hung.


    Run a network sniffer such as ethereal and see what is being blocked. Look
    at the TCP window sizes, and packet ACK numbers.

    >To test the Internet issue, I remoted into a workstation and initiated an
    >FTP session. I downloaded a 53MB file to the workstation


    >The file downloaded in about 4 minutes with no interruptions
    >that I could see. The ISP tech reported no unusual problems.


    about 221 KB/second. OK

    >I began the transfer again and pinged the router. My ping times were
    >250-400ms. This is not a good amount of time to me, so I stopped the FTP
    >and pinged the router again. This time, my ping times were 40-60ms.


    How big is the "pipe" you are trying to stuff this through. How much other
    traffic is going over that link at the same time? What kind of routers
    between you, and what priority do they give ICMP compared to TCP?
    IN THEORY, you can reduce the size of the packets, which increases the
    overhead of the connection, but does allow more spaces between the packets
    to slip in your ping and it's reply. However, I suspect you have some
    other problem.

    >I've repeated this experiment on other customers and did not receive these
    >results; ping times remained the same during and outside of the FTP session.


    Do they have the same sized pipe? Are they trying to stuff the same amount
    of stuff over the link at the same time? Does one have a bunch of clueless
    fools who are mailing PowerPoint presentations back and forth, or running
    HTML instead of plain text?

    >Please email me at rtocci@amsworld.com as well as responding to this post.


    Post here - get your answer here.

    Old guy


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