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