This read-write Integer32 (0..2147483647) is the default MBS (Maximum Burst Size) applied to new non-real-time VBR calls on the interface. An administrator sets this to control how large a burst of cells above the sustainable cell rate a non-real-time VBR connection is allowed to send before the switch's policing considers it non-conforming. For example, increasing cwspDefaultMbsNrtVbr permits non-real-time VBR sources to send longer bursts at their peak rate during setup, which is useful for bursty applications riding VBR service that would otherwise be shaped too aggressively.