The ifIndex value that is associated with this instance of the ntnQosPolicyPrecResDiagsEntry. The ifIndex value of this attribute corresponds to the ifTable entry with the same ifIndex value. When resources are centrally allocated and not port-based, a series of interfaces is typically associated with a bank or slice of filter (rule), meter and counter resources. Interfaces associated with the same slice will have the same values for the returned resource usage data.