TcpInitialRTT

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\<interface-name>

Data type Range Default value
REG_DWORD 0x0 - 0xFFFF 0x3

Description

Determines how quickly TCP retransmits a connection request if it doesn't receive a response to the original request for a new connection.

This value initializes the retransmission timer. It specifies the time that must elapse between the original transmission and the first retransmission. On each subsequent retransmission, the previous interval is doubled. This strategy assumes that the response is delayed because the connection is slow.

By default, the retransmission timer is initialized to 3 seconds, and the request (SYN) is sent twice, as specified in the value of TcpMaxConnectRetransmissions.

Note Image Note

Windows 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.

Caution Image Caution

Because the delay between retransmissions grows exponentially, this initial value should be very small. Entering a value greater than 3 (seconds) prevents the server from disposing of unacknowledgeable connection requests expeditiously.