{HEAD ~ One such modem} is typically located at {TAIL ~ a customer premises} such as a home or business and is “downstream” from a central office with which it communicates 
is typically located at
{ HEAD ~ One such modem } is typically located at { TAIL ~ a customer premises } such as a home or business and is “ downstream ” from a central office with which it communicates
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH