In other embodiments, the primary communications test includes the issuer of the test request sending yet another message, in {HEAD ~ response} to receiving {TAIL ~ the test reply} 
to receiving
In other embodiments , the primary communications test includes the issuer of the test request sending yet another message , in { HEAD ~ response } to receiving { TAIL ~ the test reply }
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 REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL