Normally, what would happen.
Legend: S = Server. C = Client.
1. C: Hey Server, wanna connect & send data? [SYN]
2. S: Oh yeah, tell me when you're ready [SYN-ACK]
3. C: Ready now! [ACK]
What happens on a timeout error:
1. C: Hey Server, wanna connect & send data? [SYN]
. . . -wait-
. . .
. . .
. . .
2. C: Ugh fine, I quit, you won't talk to me! :C [605 Timeout]