The PFC feature provides "no-drop" packet delivery for certain traffic classes while maintaining existing LAN behavior for other traffic classes on a converged link. Priority 3 is enabled by default for flow control. In order to efficiently utilize switch resources, the switch allows up to two priorities for Ethernet priority pause. The Ethernet per-priority pause is applied only to PFC packets.
The PFC feature is a symmetric exchange feature. This means that the desired PFC configuration for the peer must match the local PFC configuration.