Importantly, {HEAD ~ all node switches} share {TAIL ~ a common optical fiber} and thus interface losses are avoided 
share
Importantly , { HEAD ~ all node switches } share { TAIL ~ a common optical fiber } and thus interface losses are avoided
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH