Separately using the URN the ALR contacts the HLR to make {HEAD ~ a validity check} 117 of {TAIL ~ the URL} 
Separately using the URN the ALR contacts the HLR to make { HEAD ~ a validity check } 117 of { TAIL ~ the URL }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL