If set to 1, TCP always sends a SYN segment with the timestamp option. If set to 2, timestamps are completely disabled, regardless of whether the TCP connection was opened actively or passively. Note that if TCP receives a SYN segment with the timestamp option, TCP responds with a SYN segment with the timestamp option even if the parameter is set to 0.
0 (disabled), 1 (enabled), or 2 (disabled regardless of how TCP connection was opened)
If getting an accurate measurement of round-trip time (RTT) and TCP sequence number wraparound is a problem, enable this parameter.
Refer to RFC 1323 for more reasons to enable this option.