Question: What is the primary purpose of the CSC-21 reference point between MC gateway servers in different Mission Critical (MC) systems across distinct security domains?
Option 1: To facilitate the sharing of subscription and notification-related signaling for group configuration, user configuration management, and location management.
Option 2: To enable direct media transfer between User Equipment (UE) in different MC systems.
Option 3: To manage Quality of Service (QoS) parameters for mission-critical communications across different networks.
Option 4: To authenticate and authorize users moving between different MC systems.
Explanation: The CSC-21 reference point is crucial for interoperability and seamless service continuity between different Mission Critical (MC) systems. By sharing subscription and notification-related signaling, it supports group configuration, user configuration management, and location management. This enables effective interconnection and migration of services between MC systems, which is vital for public safety and other mission-critical use cases where continuity of service is paramount.