TCP Tracing

Hi all,
I'm trying to have a detailed information of different TCP operations
(congestion control algorithms) in freeBSD. I have to get a log file
that
tells me each time TCP enters or exits a certain step of its congestion
control algorithm (slow-start, fast recovery, ......) and a time stamp
of that action.

Is there any idea about how to do this and which function to use
(tcp_input, tcp_out, ..... )

Your help will be really appreciated,
Thanks in advance,
Alaa

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