def set_all_traffic_item(self,enabled=True):
    """ Enables/Disables *all* traffic items at once
    """

    cli = self._clients[self._cur_name]
    ix  = cli['connection']

    traffic_items = ix.getList(ix.getRoot()+'traffic','trafficItem')
    for item in traffic_items:
        result = ix.setAttribute(item,'-enabled',enabled)
        if result != '::ixNet::OK': return False
    ix.commit()
 
    return True