{HEAD ~ The SIP data} is sent to {TAIL ~ a corresponding destination network node} using NAS control information included in the NAS control message 
is sent to
{ HEAD ~ The SIP data } is sent to { TAIL ~ a corresponding destination network node } using NAS control information included in the NAS control message
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH