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