Table 181 shows
the forwarding class and packet loss priority (PLP) that are assigned
by default to each well-known DSCP. Although several DSCPs map to
the expedited-forwarding (ef) and assured-forwarding (af) classes, by default no resources are assigned to these
forwarding classes. All af classes other than af1x are mapped to best-effort, because RFC
2597, Assured Forwarding PHB Group, prohibits
a node from aggregating classes. Assignment to best-effort implies that the node does not support that class.