By way of example, less important data such as correspondence is transferred by packet switching and {HEAD ~ audio data} is transferred by {TAIL ~ line switching} 
is transferred by
By way of example , less important data such as correspondence is transferred by packet switching and { HEAD ~ audio data } is transferred by { TAIL ~ line switching }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL