TcpTimedWaitDelay

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

Data type Range Default value
REG_DWORD 0x1E- 0x12C (30 - 300) seconds 0xF0 (240 seconds = 4 minutes)

Description

Determines the time that must elapse before TCP can release a closed connection and reuse its resources. This period between closure and release is known as the TIME_WAIT state or 2MSL state. During this time, the connection can be reopened at much less cost to the client and server than establishing a new connection.

RFC 793 requires that TCP maintain a closed connection for an interval at least equal to twice the maximum segment lifetime (2MSL) of the network. When a connection is released, its socket pair and TCP control block (TCB) can be used to support another connection. By default, the MSL is defined to be 120 seconds, and the value of this entry is equal to two MSLs, or 4 minutes. However, you can use this entry to customize this interval.

Reducing the value of this entry allows TCP to release close connections faster, providing more resources for new connections. However, if the value is too low, TCP might release connection resources before the connection is complete, requiring the server to use additional resources to reestablish the connection.

Note Image Note

Normally, TCP does not release closed connections until the value of this entry expires. However, TCP can release connections before this value expires if it is running out of TCP control blocks (TCBs). The number of TCBs the system creates is specified by the value of MaxFreeTcbs.

Windows 2000 does not add this entry to the registry. You can add it by editing the registry or by using a program that edits the registry.

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