driver performance of CoNDIS WAN driver (poor performance).

Discussion in 'Windows Vista Drivers' started by Angie, Nov 21, 2007.

  1. Angie

    Angie Guest


    I am developing a CoNDIS WAN driver. Basically, this driver is a virtual
    VPN driver, which tunnles network traffic to a SSL VPN. Inside the driver,
    it calls TDI API to send/receive the packet to/from application. We have
    a similar old driver which was implemented with NDIS WAN driver. This driver
    uses the same mechanizm to comunicate betwwen driver and application. The
    only difference is the NDIS driver interfaces and API used by those two

    When I run a utility called "PCATTCP" to test the TCP TX on both new and old
    driver. To my surprise, the performance of the new driver (CoNDIS WAN) is

    20 times slower in XP and
    50 times slower in Vista.

    I run the Network Monitor to capture the packets and found only a few
    re-send packets. In addition, I ran "Kernrate" tool to analyze the driver
    performance and find no clues.
    Can anyone give a suggetion to anylze why CoNDIS WAN is tremedously slow in
    TCP Transmition test or tell me how to tune it? I examined my driver several
    times and could not find where my driver could casue such a problem.
    Angie, Nov 21, 2007
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  2. Any QoS packet scheduler (psched) issues, maybe? Try and disable or de-
    install the packet scheduler service.

    Stephan Wolf [MVP], Nov 21, 2007
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  3. Angie

    Angie Guest

    I uninstalled the psched driver and it makes no difference. I really do not
    know what Microsoft makes between


    The only difference I changed it to comply with the CoNDIS driver spec. As
    Microsoft claims, CoNDIS WAN should perform better than NDIS WAN but it is
    not true in reality.
    What even the worst is that CoNDIS 6.0 (For Vista) even worst than CoNDIS
    5.0. Should I ask Mircost's support engineer why the performance of the
    ConDIS WAN driver is
    so bad?
    Angie, Nov 22, 2007
  4. Stephan Wolf [MVP], Nov 22, 2007
  5. Angie

    Angie Guest

    Good suggestion. I will run NDISTest and see if I can get some clues.
    Angie, Nov 26, 2007
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