Which QoS feature uses the IP Precedence bits in the ToS field of the IP packet header to partition traffic into different priority levels?

Marking is the act of setting or modifying the QoS fields (like IP Precedence or DSCP) in a packet, which typically occurs *after* traffic has been classified, not the act of using them to identify traffic.

Shaping is a mechanism to smooth out traffic bursts and limit the output rate of traffic, delaying packets if necessary, and it operates *after* classification and marking.

Policing enforces traffic rates by dropping or remarking packets that exceed a configured limit, acting on traffic *after* it has been classified and potentially marked.

Classification is the initial step in QoS, where traffic is identified and categorized based on various criteria, including the IP Precedence bits within the ToS field, allowing it to be assigned to different priority levels for subsequent QoS actions.