You are asked to design a traffic policy to restrict traffic leaving a customer site. Which technique is recommended to enforce a traffic leaving the site?

WRED is a congestion avoidance mechanism that probabilistically drops packets to signal TCP to slow down, not a tool for enforcing an outbound traffic rate at a site boundary.

Class-based policing enforces rate limits by dropping or remarking excess traffic rather than buffering it, causing packet loss instead of smoothly restricting the egress rate.

Policy routing steers packets to alternate paths based on match criteria such as source address or packet size, but does not control or limit the rate of traffic leaving a site.

Traffic shaping regulates the rate of traffic leaving an interface by queuing excess packets and releasing them at a configured rate, which smooths bursts rather than discarding them. This makes it the standard recommendation for enforcing outbound bandwidth limits at a customer WAN edge, as it avoids packet loss while still conforming to a contracted rate.