Glad to hear that setting TcpAckFrequency to one was helpful. However, that setting doesn't disable the Nagle Algorithm. It adjusts an optimization called Delayed Acks which interacts with Nagle but isn't the same as Nagle.

There's a lot of advice on forums saying you can disable the Nagle Algorithm globally by setting a different registry option, TCPNoDelay, to one. I always assumed this advice is true because there is a related option called TCP_NODELAY that applications programmers can use to turn off Nagle for their particular socket connections. For example, I use TCP_NODELAY in HotkeyNet to speed up HotkeyNet's transmissions when it sends commands to other copies of HotkeyNet. So it made sense that Microsoft would have a registry option with a similar name that does the same thing for all programs at once.

However a few minutes ago I looked up TCPNoDelay on Microsoft's website and read the documentation. The documentation says that TCPNoDelay sets Nagling for a Microsoft service called Microsoft Message Queuing. It's not clear whether that service affects all app's globally (including WoW) or only connections that make explict use of that service.

Microsoft articles about adjusting Delayed Acks with TcpAckFrequency:
http://support.microsoft.com/kb/328890
http://msdn.microsoft.com/en-us/library/aa505957.aspx

Microsoft article about disabling Nagle Algorithm with TCPNoDelay:
http://www.microsoft.com/technet/pro....mspx?mfr=true
http://technet.microsoft.com/en-us/l.../cc783904.aspx