This attribute specifies the default usage parameter control (UPC) option for connections of the ABR service category. An override to this default may be specified for a provisioned connection under the Vcd Tm or Vpd Tm component.

For ATM IP cards, if this attribute is set to enforced, UPC for ABR connection is enforced as a Dynamic Generic Cell Rate Algorithm (DGCRA) based on the connection traffic descriptor.

For CQC-based ATM cards, if this attribute is set to enforced, the connection enforces a single GCRA policer at the defined PCR and CDVT for this connection.

When UPC is enforced on an ABR connection, non-conforming cells are discarded.

On ATM IP FPs, when this attribute is set to monitored, UPC conformance checking is performed, except, instead of the non- conforming cells being discarded, they are merely counted in the UPC violations counts, and passed on unchanged.

On CQC-based ATM FPs, when this attribute is set to monitored, it has the same effect as setting it to disabled.

When this attribute is set to disabled, UPC is disabled on the receive path for all ABR connections.

This attribute does not apply to standard Vpt Vccs and basic Vpts.