This read-write Integer32 (0..2147483647) is the default MBS (Maximum Burst Size) applied to new real-time VBR (Variable Bit Rate) calls on the interface. An administrator sets this to control how large a burst of cells above the sustainable cell rate a real-time VBR (Variable Bit Rate) connection is allowed to send before the switch's policing considers it non-conforming. For example, increasing cwspDefaultMbsRtVbr permits real-time VBR (Variable Bit Rate) 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.