The BGP MED attribute, commonly referred to as the BGP metric, provides a means to convey to a neighboring Autonomous System (AS) a preferred entry point into the local AS. BGP MED is a non-transitive optional attribute and thus the receiving AS cannot propagate it across its AS borders. The BGP community can also contain both AS and IP precedence information — see the second example below. After classification, other QoS features such as CAR and WRED can then be used to enforce business policy. Note that this allows you to set up a policy at one BGP speaking router, and propagate that to other routers via BGP. Hence the name.