However, the aforementioned notification mechanisms are utilized in {TAIL ~ yet other embodiments} to confirm the existence of a fully functional bi directional path using only a test request and a test reply—or via {HEAD ~ separate tests} initiated by issuing a test request from each redundant network access point of a node  
However , the aforementioned notification mechanisms are utilized in { TAIL ~ yet other embodiments } to confirm the existence of a fully functional bi directional path using only a test request and a test reply — or via { HEAD ~ separate tests } initiated by issuing a test request from each redundant network access point of a node
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH