jitter awk scripts

BEGIN {

         num_recv=0

   }

  {

              # Trace line format: new

       if ($2 == "-t") {

             event = $1

             time = $3

             node_id = $5

             flow_id = $39

             pkt_id = $41

             pkt_size = $37

             flow_t = $45

             level = $19

       }

  # Store packets send time

  if (level == "AGT" &&
sendTime[pkt_id] == 0 && (event == "+" || event ==
"s") && pkt_size >= 512) {

       sendTime[pkt_id] = time

  }

  # Store packets arrival time

  if (level == "AGT" && event
== "r" && pkt_size >= 512) {

             recvTime[pkt_id] = time

             num_recv++

       }

  }

  END {

       # Compute average jitter

       jitter1 = jitter2 = tmp_recv = 0

       prev_time = delay = prev_delay =
processed = 0

       prev_delay = -1

       for (i=0; processed<num_recv; i++) {

             if(recvTime[i] != 0) {

                     tmp_recv++

                  if(prev_time != 0) {

                       delay = recvTime[i] -
prev_time

                       e2eDelay = recvTime[i] -
sendTime[i]

                       if(delay < 0) delay =
0

                       if(prev_delay != -1) {

                       jitter1 += abs(e2eDelay -
prev_e2eDelay)

                       jitter2 +=
abs(delay-prev_delay)

                       }

                       prev_delay = delay

                       prev_e2eDelay = e2eDelay

                  }

                  prev_time = recvTime[i]

             }

             processed++

       }

  }

  END {

         printf("Mean Jitter =
%.2f\n",jitter1*1000/tmp_recv);

         printf("Current Jitter =
%.2f\n",jitter2*1000/tmp_recv);

  }

  function abs(value) {

       if (value < 0) value = 0-value

       return value

  }