However, as soon as the controller detects an outgoing long distance call which commences with a digit 1, the controller inserts a prefix or access code to the dialed number to connect {HEAD ~ the subscribers telephone unit} with a long distance provider or {TAIL ~ carrier} in accordance with the desired algorithm 
with
However , as soon as the controller detects an outgoing long distance call which commences with a digit 1 , the controller inserts a prefix or access code to the dialed number to connect { HEAD ~ the subscribers telephone unit } with a long distance provider or { TAIL ~ carrier } in accordance with the desired algorithm
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH