The receipt and processing of the communication packet may be acknowledged by {HEAD ~ the central controller} to {TAIL ~ computer}  
The receipt and processing of the communication packet may be acknowledged by { HEAD ~ the central controller } to { TAIL ~ computer }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL OTH