A customer plans to adopt distributed QoS in their enterprise WAN. The policy must allow for individual packet marking according to the type of treatment required and for forwarding based on…

Class-Based Weighted Fair Queuing (CBWFQ) is a queuing mechanism, not a comprehensive end-to-end QoS architecture that dictates how packets are marked and handled across an entire WAN.

Low Latency Queuing (LLQ) is a specific queuing feature that combines priority queuing with CBWFQ, but it is not an end-to-end QoS architecture like DiffServ.

Differentiated Services (DiffServ) is a scalable QoS model that marks individual packets with a DSCP value, allowing each network device to apply locally defined, hop-by-hop treatment based on this marking without per-flow state. This distributed approach is ideal for large enterprise WANs.

Integrated Services (IntServ) provides end-to-end QoS guarantees with per-flow state and signaling (RSVP), which does not scale well in large enterprise WANs due to the overhead of maintaining state for every flow.