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