A database administrator experiences delay when performing storage replication between primary and secondary data centers.

A database administrator experiences delay when performing storage replication between primary and secondary data centers. The data centers are located 20 kilometers apart and are connected using a 500 Mbps link. The deployment was implemented using an FCIP tunnel and a pair of Cisco MDS 9250 Series Switches. The network engineer decided to enable QoS to prioritize replication traffic. Which QoS model must be used to resolve the performance issues?