Data type Range Default value
REG_DWORD 0x0 - 0xFFFFFFFF retransmission attempts 0x5


Determines how many times TCP retransmits an unacknowledged data segment on an existing connection. TCP retransmits data segments until they are acknowledged, or until this value expires.

TCP/IP adjusts the frequency of retransmissions over time. TCP establishes an initial retransmission interval by measuring the round-trip time on the connection. The interval is doubled with each successive retransmission on a connection and is reset to the initial value when responses resume.

TcpMaxDataRetransmissions also is used in the Windows algorithm for defining non-operational ("dead") gateways.

Any given connections defines a gateway as dead (and switches to the next gateway in the list in DefaultGateway or DhcpDefaultGateway) when a packet sent to the gateway must be retransmitted more than half of the number of times specified in the value of TcpMaxDataRetransmissions. The system defines a gateway as dead when more than 25% of its connections have switched to the next default gateway in the list.

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TcpMaxDataRetransmissions determines how many times TCP retransmits data segments. The maximum number of retransmissions of requests for new connections is determined by the value of TcpMaxConnectRetransmissions.

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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