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