Which option describes the message that establishes the direct tunnel between RNC and
GGSN?
A.
SGSN context request/response and modify PDP context request/response
B.
SGSN: Initiated update PDP context request/response and RAB assignment
request/response
C.
GGSN: Initiated update PDP context request/response and RAB assignment
request/response
D.
SGSN: Initiated update PDP context request/response and modify PDP context
request/response