This sets the absolute maximum length of the CBR queue, beyond which the card discards all cells regardless of CLP marking, unlike cardClp0CbrThreshold which only discards CLP-1 cells first. This is the hard ceiling that only gets reached if the earlier CLP-1-only discard threshold already failed to relieve enough pressure, so an admin seeing discards attributable to this threshold knows the CBR queue is overwhelmed badly enough that even guaranteed CLP-0 traffic is now being lost, a more severe condition than the earlier selective discard. For example, discards attributable to cardClp01CbrThreshold being reached indicate the CBR queue overflowed so severely that even non-discard-eligible voice cells were lost, a more serious event than the earlier CLP-1-only shedding.