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