KB 949316 - Add Compound TCP (CTCP) support to XP and Server 2003 (original) (raw)

A hotfix is available to add Compound TCP (CTCP) support to computers that are running Windows Server 2003 or Windows XP. CTCP aggressively adjusts the congestion window of the sender to optimize TCP for connections with large bandwidth-delay products. These products include Video on Demand for Windows Server 2003 and for Windows XP.

Note: CTCP support was introduced in Windows Vista and in Windows Server 2008.
Personal note: I'll be adding this to my XP VMs, 2003 VMs, and standalone machines that are at home because CTCP has proven to be a win, performance wise, for my Internet connection.

Once the hotfix is applied, ensure CTCP is enabled by checking the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TCPCongestionControl. It should be set to 1 as a DWORD to enable.