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