Question: What is a key responsibility of the Access Transfer Control Function (ATCF) during a call, specifically in scenarios involving (v)SRVCC enhanced with ATCF or 5G-SRVCC?
Option 1: To modify the dynamic Session Transfer Identifier (STI) exchanged between the User Equipment (UE) and the Service Centralization and Continuity (SCC) Application Server (AS).
Option 2: To keep track of sessions (pre-alerting, alerting, active, or held) for performing Access Transfer of the selected session.
Option 3: To directly manage media codec negotiations between the UE and the network during access transfers.
Option 4: To always remove the Access Transfer Gateway (ATGW) from the media path after Access Transfer, without considering local policy.
Explanation: The correct answer is Option 2 because one of the primary functions of the ATCF is to keep track of sessions to perform Access Transfer of the selected session. This highlights the ATCF's role in managing and coordinating access transfers seamlessly.