[ns] How do you recognize the last packet?

[Jahan Hassan <jahan@cse.unsw.edu.au>]

Hi All,
In my simulation, I'm using Agent TCP, and application
FTP.
FTP has 'produce n' command that sets the counter of
packets to be sent to n.

So, if I have TCP packet size = 1000 and if I use 'produce 100'
for FTP, that should give me 1000*100 bytes of transmission, right?

What I'd like to do is measure how much time it took for the
transmission (ie, the file transfer delay).
I was thinking of taking the ts_ of the first packet
(where the seqno_ ==0), then take the $now for WHEN the
last packet is received (in the tcpsink). Now, HOW can I
detect the last packet ?
Any clues/ideas?

You see what I'm trying to do, do you have any solution for this?
Thanks in advance for your help.

Regards,
Jahan.