none
TCP Window Size

    Question

  • When needing to increase the TCP Window Size in an Infrastructure that supports Windows Scaling, which is the best option - enable Windows Scaling and set the shift count or to hardcode setting the TcpWindowSize registry value?  Are there any consequences of doing one method over the other?  Thanks.
    Tuesday, June 29, 2010 5:00 PM

Answers

  • It would seem that as long as all of your devices are RFC 1323
    compliant, that enabling scaling would be the best option because it
    allows Windows to auto-tune the receive window based on network conditions.
     
    It seems like hard coding the value could cause problems if any gateway
    devices or firewalls have issues with the scaling factor. It would also
    appear that the TcpWindowSize registry value no longer works in
    Vista/2008 and later.
     
    http://technet.microsoft.com/en-us/library/bb878127.aspx
     
    http://msdn.microsoft.com/en-us/library/ms819736.aspx
     

    -- Mike Burr
    Tuesday, June 29, 2010 7:32 PM