code: def start_packet_groups(self, clear_time_stamps=True, *ports):
          
          port_list = self.set_ports_list(*ports)
          if clear_time_stamps:
              self.api.call_rc('ixClearTimeStamp {}'.format(port_list))
          self.api.call_rc('ixStartPacketGroups {}'.format(port_list))
docs: Start packet groups on ports.
  
          :param clear_time_stamps: True - clear time stamps, False - don't.
          :param ports: list of ports to start traffic on, if empty start on all ports.