The network further includes a source of {HEAD ~ multicast packets} in {TAIL ~ a multicast session} coupled to a first node of the long haul portion 
The network further includes a source of { HEAD ~ multicast packets } in { TAIL ~ a multicast session } coupled to a first node of the long haul portion
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH