Question: When selecting an S-CSCF, if multiple S-CSCFs support all mandatory capabilities for a user, what additional factor may the I-CSCF consider to choose a specific S-CSCF?
Option 1: Optional capabilities of each S-CSCF
Option 2: Geographical location of the User Equipment (UE)
Option 3: The S-CSCF with the least current load or sessions
Option 4: Random selection among compliant S-CSCFs
Explanation: According to the S-CSCF assignment process, if more than one S-CSCF is identified that supports all mandatory capabilities for a user, the I-CSCF may then consider optional capabilities in selecting a specific S-CSCF. This ensures the best possible service for the user based on their subscription profile. Optional capabilities reflect additional features or services an S-CSCF can provide beyond the mandatory requirements.