单项选择题
Which parameter is usedby GPRST unnelling protocol between GSNs to identify a PDP context？（）
A.NSAPI B.TLLI C.SAPI D.TEID
单项选择题 Which of following interface are not using CCS7 protocol？（）
单项选择题 When a mobile of B class is on the state of standby，what MM information is registered in SGSN？（）
单项选择题 What can MS do when it is standby state？（）
