Rate decrease factor (RDF) controls the decrease in the cell Tx rate.
The value is a power of 2 from 1/32768 to 1.
Legal values are 0-15 (0==1, 15==1/32768).
The default is 4 (2**-4==1/16) as specified by af-tm-0056.000.
Note:
May not be supported on all ATM-based platforms and/or service categories.