Hi ~M,
Sorry for the late answer. From CableLabs doc :

"The QoS attributes of a Service Flow may be specified in two ways: either by explicitly defining all attributes, or
implicitly by specifying a Service Class Name. A Service Class Name is a string which the CMTS associates
with a QoS Parameter Set."

"When the Service Class Name is used in a Service Flow encoding, it indicates that all the unspecified QoS
Parameters of the Service Flow need to be provided by the CMTS. It is up to the operator to synchronize the
definition of Service Class Names in the CMTS and in the configuration file."

So basically, you configure service flows using SCN in the CMTS using CLI "configure terminal > cable > service" (see p.2-82 of "BW 3000 CLI Reference Manual"). Then use only these names in your modem configuration files to define service flows. I'm pretty sure SCN was mandatory for CMTS back to DOCSIS 1.1, it is for DOCSIS 2.0. I think Terayon put a dummy CLI functionality so they can obtain DOCSIS 2.0 certification. CableLabs never suspected it wasn't operational, or they intentionally ignored it.

For me Terayon isn't fully DOCSIS 2.0 certified. But with a lot of $$$ you can obtain anything.

Christian