TcpInitialRTT

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

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

Description

Determines how long TCP waits to retransmit a connection request if it does not 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 three seconds, and the request (SYN) is sent twice, as specified in the value of the TcpMaxConnectRetransmissions entry.

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

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