HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
| Data type | Range | Default value |
|---|---|---|
| REG_DWORD | 0 | 1 | 1 |
Enables and disables the Selective Acknowledgement (SACK) feature of Windows 2000 TCP/IP. SACK is specified in RFC 2018.
Selective Acknowledgement is an optimizing feature that lets you acknowledge receipt of individual blocks of data in a continuous sequence, rather than just the last sequence number. The recipient can tell the sender that one or more data blocks is missing from the middle of a sequence, and the sender can retransmit only the missing data.
| Value | Meaning |
|---|---|
| 0 | Disables SACK. |
| 1 | Enables SACK. |