[e2e] TCP-SYN and delayed TCB allocation

[Alok Dube]

Hi,

Maybe this has been asked several times, but i am taking the "path of least
effort" and asking :-)

Is the TCB allocated on TCP done
A)  immediately after receiving the SYN?

or

B) has it been modified that it is now done after the 1st ACK?

if not, any reason why not B? we would so the same if we had a
"NAT/Firewall" with delayed binding etc

-thanks
Alok