单项选择题
When does a MS get IP address？（）
A.After MS finishes GPRS attach B.After MS finishes PDP context activate procedure C.After MS requests RA update D.After MS finishes Cell update
单项选择题 Old SGSN can get new SGSN’s IP address by communicating to （） when a MS requests inter_SGSN RA update.
单项选择题 SGSN gets GGSN’s IP address by communicating to （） when a MS makes PDP context activation.
单项选择题 After GPRS attach，SGSN will assign an identity to identify the MS，what’s it？（）
