Question: What happens when an UPLINK NAS TRANSPORT message is received from a UE in a location where the Public Land Mobile Network (PLMN) is not allowed to operate?
Option 1: The Mobility Management Entity (MME) forwards the message to the next hop.
Option 2: The MME sends a response back to the User Equipment (UE).
Option 3: The MME discards the message.
Option 4: The MME buffers the message for later processing.
Explanation: When an UPLINK NAS TRANSPORT message is received from a UE in a location where the PLMN is not allowed to operate, the MME determines this and takes action to discard the message. This prevents any further processing of the message, ensuring that the network maintains its security and integrity by not engaging with unauthorized locations.