def start_pings(self, traffic_file):
        try:
            f = open(traffic_file, "r")
        except:
            print "Open %s failed" % traffic_file
            sys.exit(1)

        addr =  [0x20, 0x01, 0x04, 0x70, 0x1f, 0x04, 0x05, 0x6d, 
                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00];

        lines = f.readlines()
        for l in lines:
            s = l.split()
            addr[15] = int(s[1])
        
            t = TestDriverMsg()
            t.set_cmd(TEST_PING)
            t.set_dt(int(s[2]))
            t.set_n(int(s[3]))
            t.set_addr(addr)
            print int(s[0]), t
            self.sendMsg(int(s[0]), t)
            time.sleep(1)

        self.setTarget(len(lines))