Optimize the Windows TCP/IP Window Size (Windows NT/2000)

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Registry tweaks, tricks & hacks to optimize, enhance and secure Microsoft Windows.

Optimize the Windows TCP/IP Window Size (Windows NT/2000)
Category: Home > Network > Protocols > TCP-IP

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This parameter determines the maximum TCP receive window size offered by the system. The receive window specifies the number of bytes a sender may transmit without receiving an acknowledgment.

In general, larger receive windows will improve performance over high delay, high bandwidth networks. For greatest efficiency, the receive window should be an even multiple of the TCP Maximum Segment Size (MSS).

Reducing the TCP Window size effectively causes an acknowledgment to be sent to the sender for data received sooner. This will lower the possibility that the sender will time out while waiting for an acknowledgment. However it will also increase the amount of network traffic and cause slower throughput.


(Default)	REG_SZ	(value not set)
TcpWindowSize	REG_DWORD	0x00002238 (8760)


	HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

Settings:

System Key: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters]
Name: TcpWindowSize
Type: REG_DWORD (DWORD Value)
Value: 0 - 0xFFFF (default = 8760 for Ethernet)

Disclaimer: Modifying the registry can cause serious problems that may require you to reinstall your operating system. We cannot guarantee that problems resulting from modifications to the registry can be solved. Use the information provided at your own risk.

Last Modified: March 22, 2002

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