Question: What is the primary purpose of returning the Mobile-Node-Identifier AVP (AVP Code 506) in an answer message after a successful authentication and authorization exchange between the AAA client and server?
Option 1: To indicate the supported mobile IP capabilities of the 3GPP access network.
Option 2: To provide an identifier that can be used as the PMIPv6 MN-ID, MIPv4 MN-NAI, or to derive the IMSI for GTPv2 signaling.
Option 3: To inform the AAA client about the assigned local IP address for Home Before Mobility (HBM).
Option 4: To signal the support of Mobile IPv6 integrated scenario bootstrapping functionality.
Explanation: The returned Mobile Node Identifier serves multiple purposes, including being used as the PMIPv6 MN-ID, MIPv4 MN-NAI, or for deriving the IMSI to be sent in GTPv2 signaling, facilitating various mobility management and authentication processes across different network technologies.