Question: What is the primary purpose of the AAA-2 reference point between the SIP core/IMS and Diameter proxy in the context of mission critical services?
Option 1: To facilitate media transfer for group communications
Option 2: To enable QoS (Quality of Service) management for priority services
Option 3: To support service discovery for MCPTT (Mission Critical Push To Talk)
Option 4: To handle authentication and security for service layer during migration
Explanation: The AAA-2 reference point is utilized specifically for managing the security and authentication aspects when there's a need for migration, ensuring secure transitions within the service layer. This aligns with the critical need for robust security in mission-critical communications environments.