Question: Under what condition may an operator choose to bypass the default 'record-route' behavior of the S-CSCF for subsequent requests in IMS communication?
Option 1: When Application Servers under operator control guarantee home control of the session.
Option 2: For all emergency service calls to prioritize low latency.
Option 3: If the UE is roaming outside the home network.
Option 4: When the S-CSCF is experiencing high traffic congestion.
Explanation: The correct answer is Option 1 because if Application Servers under operator control guarantee the home control of the session, it may not be required for all subsequent requests to traverse the S-CSCF, allowing the operator to choose bypassing the default 'record-route' behavior.