This has the advantage that {HEAD ~ data} can be transferred simultaneously by {TAIL ~ packet switching} and line switching 
transferred simultaneously by
This has the advantage that { HEAD ~ data } can be transferred simultaneously by { TAIL ~ packet switching } and line switching
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH