Question: In a Wireless and Wireline Convergence Access Support for the 5G System (5GS), how is QoS differentiation provided for UEs behind a Residential Gateway (RG) on a per UE basis?
Option 1: Based on the UE's IMSI in the RG's PDU Session
Option 2: On a per UE's IPsec Child Security Association basis, utilizing DSCP values in the outer IP header
Option 3: Through dedicated N6 addresses for each UE within the RG's PDU session
Option 4: By applying a single, flat QoS policy to all UEs behind the RG
Explanation: QoS differentiation for UEs behind an RG is achieved by leveraging IPsec Child Security Associations on a per UE basis. This method utilizes Differentiated Services Code Point (DSCP) values in the outer IP header of each IPsec child SA, allowing for granular QoS control as defined by the Service Level Agreement (SLA) or network configuration.