This read-create TrafficDirection object specifies a QoS Flow Policer's direction as 'a2n' or 'n2a'. Admins need to set this correctly because a policer enforcing rate limits in the wrong direction won't catch the actual traffic pattern (such as an oversubscribing customer upload) the policer was meant to control. For example, to police a customer's outbound (access-to-network) traffic against their contracted upload rate, an admin would set cmQosFlowPolicerDirection to 'a2n' on that policer instance.