Question: In a Single Network and Namespace (SNPN) supporting multiple independent IMS Providers, what information is required to be stored in the User Data Management (UDM) for each SNPN subscriber to enable IMS services?
Option 1: Subscriber's preferred P-CSCF IP address
Option 2: ISH domain name encoded as part of IMS DNN (Data Network Name)
Option 3: List of available ISHs for roaming purposes
Option 4: IMS voice over PS Session Supported Indication flags only
Explanation: To facilitate the selection of the correct P-CSCF by the SMF during PDU session setup for multiple independent IMS Providers within an SNPN, identifying information for the corresponding IMS Provider (e.g., ISH domain name) must be encoded within the IMS DNN stored in the UDM. This ensures proper routing and service provision based on the subscriber's association with a specific IMS Provider.