#This program is used to calculates the end-to-end delay and jitter of the CBR packets

BEGIN {
# Initialization. Set two arrays. start_time and end_time
    start_time[NR] = 0;
    end_time[NR] = 0;
    delay_time[NR] = 0; #will hold the delay time of packet i. we will use it in the end
    last_calc = -1;     #temp var for jitter calculation
}
{
   action = $1;
   time = $2;
   from = $3;
   to = $4;
   type = $5;
   pktsize = $6;
   flow_id = $8;
   src = $9;
   dst = $10;
   seq_no = $11;
   packet_id = $12;

    if (from==1 && action == "+")               #new packet was created
        start_time[packet_id]=time;
    if (from==2 && to==3 && type=="cbr" && action == "r")   #the packet arrived
        end_time[packet_id]=time;
}
END {
    for (i=0;i<NR;i=i+1)        #scan all the array's
    {
            if(end_time[i]>0)   #if the filed in the array represent cbr packet that arrived than calculate it
            {
                delay_time[i]=end_time[i]-start_time[i];
                printf("time=%f delay=%f\n", start_time[i], delay_time[i])>"outD2.txt";
                if (last_calc>-1)
                    printf("time=%f jitter=%f\n", start_time[i], delay_time[i]-delay_time[last_calc])>"outJ2.txt";
                last_calc=i;
            }
    }
}