Passage: The GTP-C protocol is the control section of the GTP standard.  When a subscriber requests a PDP context, the SGSN will send a create PDP context request GTP-C message to the GGSN giving details of the subscriber's request.  The GGSN will then respond with a create PDP context response GTP-C message which will either give details of the PDP context actually activated or will indicate a failure and give a reason for that failure.  This is a UDP message on port 2123.

Question: What is given to the subscriber when a failure is indicated?
a reason for that failure