Microsoft has a great feature called autotuning. Autotuning though can be problematic when it comes to network connections with Microsoft Outlook, Internet Explorer 7, RDC and even some file sharing protocols over the WAN. This is mostly because not all firewalls support TCP Window Scaling for non-HTTP-based protocols.
If you’re running into problems where these applications give you errors like “Outlook is trying to retrieve data from the Microsoft Exchange Server Exchange_Server_FQDN” then you can try disabling autotuning to see if that is your problem (usually this involves wan connections, btw). To disable autotuning, use netsh to set tcp for autotuninglevel to disabled:
netsh interface tcp set global autotuninglevel=disabled
To turn autotuning back on, just set the autotuninglevel to normal:
netsh interface tcp set global autotuninglevel=normal
krypted September 28th, 2011
Posted In: Windows XP
autotuning, TCP Scaling, TCP Window Scaling, WIndow Scaling, windows, windows vista