Question: What is the primary purpose of the anonymous session establishment mechanism in IP Multimedia Subsystem (IMS) networks?
Option 1: To completely conceal user identity from all network operators involved in the session.
Option 2: To enhance security by creating additional states in Call/Session Control Function (CSCF) entities.
Option 3: To provide IMS users with the ability to withhold certain identity information from the peer party, while remaining identifiable to their own network operator.
Option 4: To simplify session establishment by bypassing Asserted Identity trust domain checks.
Explanation: The correct answer reflects the mechanism's intent. It allows users to control sharing of certain identity information with the communicating party, without being completely anonymous to their own network operator, balancing user privacy preferences with operational and security needs.