Question: Which entity typically initiates the MAP_FAILURE_REPORT service to inform about a failed network-requested PDP-context activation?
Option 1: GGSN (Gateway GPRS Support Node)
Option 2: HLR (Home Location Register)
Option 3: UE (User Equipment)
Option 4: SGSN (Serving GPRS Support Node)
Explanation: The MAP_FAILURE_REPORT service is used to notify the HLR about a failure in activating a PDP context as requested by the network. The GGSN, managing PDP contexts and interacting with the HLR for subscriber and session information, logically initiates this report in case of a failure, aligning with its role in managing data sessions and communicating with core network elements like the HLR.