The value of the object tCpmMacFltrEntryCfmOpCodeOper specifies which
type of opcode checking is to be performed.
If different fron none, more info is provided in the objects
tCpmMacFltrEntryCfmOpCodeValue1 and tCpmMacFltrEntryCfmOpCodeValue2.
This object has significance only if the object tCpmMacFltrEntryFrameType
refers to either ieee802.1ag or Y1731.