$6 !~ /^ack/ && $5 !~ /[SFR]/ 	{	# given a tcpdump ftp trace, output one line for each send	# in the form	#   <send time> <seq no>	# where <send time> is the time packet was sent (in seconds with	# zero at time of first packet) and <seq no> is the tcp sequence	# number of the packet divided by 1024 (i.e., Kbytes sent).	#	# convert time to seconds	n = split ($1,t,":")	tim = t[1]*3600 + t[2]*60 + t[3]	if (! tzero) {		tzero = tim		OFS = "\t"	}	# get packet sequence number	i = index($6,":")	printf "%7.2f\t%g\n", tim-tzero, substr($6,1,i-1)/1024	}