Enable/Disable TCP Auto Tuning


  1. Posts : 78
    Win 7 Home Premium-64bit
       #1

    Enable/Disable TCP Auto Tuning


    Wondering what is best...Enable/Disable TCP Auto Tuning?:)
      My Computer


  2. NoN
    Posts : 4,166
    Windows 7 Professional SP1 - x64 [Non-UEFI Boot]
       #2

    canspec said:
    Wondering what is best...Enable/Disable TCP Auto Tuning?:)
    Should have you explain us more...Looks for Vista:

    Disable TCP Auto-Tuning to Solve Slow Network, Cannot Load Web Page or Download Email Problems in Vista My Digital Life

    Vista Tutorial
    http://www.vistax64.com/tutorials/72...ive-level.html
      My Computer


  3. Posts : 78
    Win 7 Home Premium-64bit
    Thread Starter
       #3

    NoN said:
    canspec said:
    Wondering what is best...Enable/Disable TCP Auto Tuning?:)
    Should have you explain us more...Looks for Vista:

    Disable TCP Auto-Tuning to Solve Slow Network, Cannot Load Web Page or Download Email Problems in Vista My Digital Life

    Vista Tutorial
    Auto Tuning - TCP/IP receive level - Vista Forums
    Disable Windows Scaling heuristics
    Windows Vista/7 has the ability to automatically change its own TCP Window auto-tuning behavior to a more conservative state regardless of any user settings. It is possible for Windows to override the autotuninlevel even after an user sets their custom TCP auto-tuning level. When that behavior occurs, the "netsh int tcp show global" command displays the following message:
    ** The above autotuninglevel setting is the result of Windows Scaling heuristics
    overriding any local/policy configuration on at least one profile.
    To prevent that behavior and enforce any user-set TCP Window auto-tunning level, you should execute the following command:
    netsh int tcp set heuristics disabled
    possible settings are: disabled,enabled,default (sets to the Windows default state)
    recommended: disabled (to retain user-set auto-tuning level)
    Note this should be executed in elevated command prompt (with admin priviledges) before setting the autotuninlevel in next section. If the command is accepted by the OS you will see an "Ok." on a new line.

    TCP Auto-Tuning
    To turn off the default RWIN auto tuning behavior, (in elevated command prompt) type:
    netsh int tcp set global autotuninglevel=disabled
    The default auto-tuning level is "normal", and the possible settings for the above command are:
    disabled: uses a fixed value for the tcp receive window. Limits it to 64KB (limited at 65535).
    highlyrestricted: allows the receive window to grow beyond its default value, very conservatively
    restricted: somewhat restricted growth of the tcp receive window beyond its default value
    normal: default value, allows the receive window to grow to accommodate most conditions
    experimental: allows the receive window to grow to accommodate extreme scenarios (not recommended, it can degrade performance in common scenarios, only intended for research purposes. It enables RWIN values of over 16 MB)
    Our recommendation: normal (unless you're experiencing problems).
    If you're experiencing problems with your NAT router or SPI firewall, try the "restricted", "highlyrestricted", or even "disabled" state.
    Notes:
    - Reportedly, some older residential NAT routers with a SPI firewall may have problems with enabled tcp auto-tuning in it's "normal" state, resulting in slow speeds, packet loss, reduced network performance in general.
    - auto-tuning also causes problems with really old routers that do not support TCP Windows scaling. See
    MSKB 935400
    - netsh set commands take effect immediately after executing, there is no need to reboot.
    - sometimes when using "normal" mode and long lasting connections (p2p software / torrents), tcp windows can get very large and consume too much resources, if you're experiencing problems try a more conservative (restricted) setting.

    If you're experiencing problems with Auto-Tuning, see also:
    MS KB 835400 - email issues
    MS KB 934430 - network connectivity behind firewall problems
    MS KB 940646 - 3G WWAN throughput issues
    MS KB 929868 - web browsing issues
    MS KB 932170 - slow network file transfer
      My Computer


  4. NoN
    Posts : 4,166
    Windows 7 Professional SP1 - x64 [Non-UEFI Boot]
       #4

    Try before to not allow ICMP in your firewall center => advanced parameters => IPsec Parameters, this will resolve some network connections problems if you don't need Icmp.

    In registry editing:
    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters
    Value DWORD 32bits: EnableICMPRedirect set to "0"

    This will be handy aswell to prevent an attack on Icmp, so it helps both "Connectivity & Security"


    At the end of the MS KB934430 you've got a tool to test connectivity:
    Internet Connectivity Evaluation Tool

    This tool may help you in your request & your choices:)
    Looks not manies have done what you're asking yet.


    canspec, don't blame me i perfectly understand what you want...but every pc have their own way as broadband might not have all the same settings.
    http://www.speedguide.net/read_articles.php?id=2574

    I know speedguid.net since ages and they provide some usefull infos.
    Last edited by NoN; 29 Mar 2010 at 14:56. Reason: editing
      My Computer


 

  Related Discussions
Our Sites
Site Links
About Us
Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

© Designer Media Ltd
All times are GMT -5. The time now is 05:16.
Find Us