The method 1, wherein the old and the new packet data support {HEAD ~ node comprise SGSN} and {TAIL ~ CGSN} 
The method 1 , wherein the old and the new packet data support { HEAD ~ node comprise SGSN } and { TAIL ~ CGSN }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL