The accessor location register 4 herein said controller contacts a visitor location register corresponding to said second URL for information relevant to the communications unit in {HEAD ~ order} to initiate said third contact attempt and to cause {TAIL ~ said visitor location register} to start a session with the communications unit 
to cause
The accessor location register 4 herein said controller contacts a visitor location register corresponding to said second URL for information relevant to the communications unit in { HEAD ~ order } to initiate said third contact attempt and to cause { TAIL ~ said visitor location register } to start a session with the communications unit
OTH OTH OTH OTH OTH 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 OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH