This enables or disables outright filtering, that is, blocking, of all packets matched by this QoS rule, rather than shaping or prioritizing them. Unlike WRED's selective congestion-based dropping, enabling this filter flag drops every single packet matching the rule's criteria unconditionally; this is the setting behind the cdmipDroppedPacketsQosFilterRule counter, effectively making this a firewall rule dressed up as a QoS rule. For example, enabling Filter on a rule matching a known malicious source IP address blocks 100% of that traffic outright, unlike a low-priority rule, which would merely deprioritize it.