Which two features are implemented on the Packet Forwarding Engine?

The Packet Forwarding Engine (PFE) is specifically designed to handle high-speed packet processing in Junos devices, mainly focusing on the efficient forwarding of traffic based on predefined rules. Class of Service (CoS) is an essential feature implemented on the PFE, allowing for the differentiation of traffic types and prioritizing them accordingly. This feature is crucial for ensuring Quality of Service (QoS), enabling the network to handle traffic more effectively by assigning different treatment levels to various types of traffic, such as voice, video, or standard data.

In contrast, dynamic routing protocols, firewall filters, and network address translation (NAT) are typically handled by the Routing Engine (RE) or a combination of both the RE and PFE, but they are not core functions of the PFE itself. While these functionalities may interact with the data processing done by the PFE, their primary implementation and management occur outside its dedicated packet forwarding tasks. Thus, the implementation of Class of Service directly aligns with the core capabilities of the Packet Forwarding Engine, making it the correct response.