1$6 ~ /^ack/ && $5 !~ /[SFR]/  {
2          # given a tcpdump ftp trace, output one line for each ack
3          # in the form
4          #   <ack time> <seq no>
5          # where <ack time> is the time packet was acked (in seconds with
6          # zero at time of first packet) and <seq no> is the tcp sequence
7          # number of the ack divided by 1024 (i.e., Kbytes acked).
8          #
9          # convert time to seconds
10          n = split ($1,t,":")
11          tim = t[1]*3600 + t[2]*60 + t[3]
12          if (! tzero) {
13                    tzero = tim
14                    OFS = "\t"
15          }
16          # get packet sequence number
17          printf "%7.2f\t%g\n", tim-tzero, $7/1024
18          }
19