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