If set to 'true' and when the CM signals to the CMTS 'Upstream Drop Classifier Group ID' encodings, this attribute instructs the CMTS MAC Domain to send the Subscriber Management Filters rules associated with the 'Upstream Drop Classifier Group ID' encodings to the CM in the form of UDCs when the following conditions occurs: - The attribute CmUdcEnabled value for this MAC Domain is set to 'true', and - The CM has the UDC capability advertised as supported. If there is no a single Subscriber Management Filter configured in the CMTS for the CM's signaled UDC Group ID, the CMTS does not send UDC encodings to the CM.

It is vendor specific whether the CMTS maintains enforcement of the CM signaled or default Subscriber Management Filter groups in the upstream direction.