This read-write integer (0..64) is the Cutoff Decrease Factor for a standard-ABR connection, a unitless value that must be inverted to get the actual factor, restricted to 0 or powers of 2 (1, 2, 4, ... 64) with agent-enforced compliance. An administrator sets CDF to control how the source's allowable cell rate is cut back when the connection has been idle longer than the ADTF timeout. For example, setting frstdABRCDF to 0 disables the cutoff-decrease behavior entirely, whereas setting it to 64 applies the most aggressive decrease among the valid power-of-2 options.