Cisco ENCOR Practice Exam 2025 – All-in-One Comprehensive Guide to Mastering Enterprise Network Core Technologies!

The Assured Forwarding (AF) service in Differentiated Services (DiffServ) is designed to provide a level of quality assurance in the treatment of packets based on defined forwarding classes. Specifically, Assured Forwarding groups packets into different classes that can receive varying levels of service assurance.

The function of AF is to ensure that a certain amount of bandwidth is guaranteed for the traffic in those classes, enabling applications that are sensitive to network performance—such as voice and video—to operate more effectively. This is achieved through mechanisms that allow for the controlled dropping of packets when congestion occurs, ensuring that those with higher priority are less likely to be discarded, thus providing a predictable level of bandwidth.

This specific focus on guaranteeing bandwidth differentiates AF from other diffserv services that may prioritize low delay but do not ensure bandwidth, or offer uniform treatment across all packets without prioritization. In contrast, providing a best-effort service does not involve any guarantee of bandwidth or performance levels, which further emphasizes the unique role of Assured Forwarding in managing network traffic effectively.