Loss priorities allow you to set the priority of dropping a packet. You can use the loss priority setting to identify packets that have experienced congestion. Typically, you mark packets exceeding some service level with a high loss priority—a greater likelihood of being dropped. You set loss priority by configuring a classifier or a policer. The loss priority is used later in the work flow to select one of the drop profiles used by random early detection (RED).
You can configure the packet loss priority (PLP) bit as part of a congestion control strategy. The PLP bit can be configured on an interface or in a filter. A packet for which the PLP bit is set has an increased probability of being dropped during congestion.