This attribute represents the maximum sustained traffic rate allowed for this Service Flow in bits/sec. It represents all MAC frame data PDUs from the bytes following the MAC header HCS to the end of the CRC. The number of bytes forwarded is limited during any time interval. The value 0 means no maximum traffic rate is enforced. This attribute applies to both upstream and downstream Service Flows. This attribute returns 0 if the referenced parameter is not present in the corresponding DOCSIS QOS Parameter Set, or if the parameter is not applicable. This attribute will also return 0 if DataRateUnitSetting is enabled and the resulting value cannot be represented in 32 bits. In which case, docsQosParamSetHCMaxTrafficRate should be utilized.