The quality of service module is configured to check whether {HEAD ~ the received data traffic} for the ONU has {TAIL ~ a high priority and low bandwidth requirement} 
has
The quality of service module is configured to check whether { HEAD ~ the received data traffic } for the ONU has { TAIL ~ a high priority and low bandwidth requirement }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL