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