The three message primary test sequence confirms the existence of a fully functional bi directional path between the two access points of {TAIL ~ a node} redundantly connected to {HEAD ~ a network} 
The three message primary test sequence confirms the existence of a fully functional bi directional path between the two access points of { TAIL ~ a node } redundantly connected to { HEAD ~ a network }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD