Question: In a Mission Critical (MC) service scenario utilizing topology hiding, what authorizations are required for an MC service client to affiliate with an MC service group defined in a partner MC system for a single MC service?
Option 1: Only authorization from the serving MC system of the MC service client is required.
Option 2: Authorization from the partner MC system where the MC service group is defined, but not necessarily from the serving MC system.
Option 3: Authorizations from both the partner MC system (where the MC service group is defined) and potentially from the serving MC system of the MC service client are required.
Option 4: No authorization is needed for affiliation in topology hiding scenarios.
Explanation: In Mission Critical services, especially when involving external systems (partner MC system) and utilizing features like topology hiding to maintain privacy and security, dual-layered authorization ensures the integrity of both the client's serving network and the partner network's resources. This approach safeguards against unauthorized access while facilitating cooperative service delivery across different MC systems. Thus, requiring authorizations from both the partner MC system (to protect its defined groups) and potentially from the serving MC system (to validate the client's eligibility) is a comprehensive security measure.