C3 Maximum Data Frame Size.
The maximum data frame size which this client will
use the next time it returns to the Initial State.
Auto-configuring clients use this parameter in their
Configure requests. Manually-configured clients use
it in their Join requests.
This MIB object will not be overwritten with the new
value from a LE_{JOIN,CONFIGURE}_RESPONSE. Instead,
lecActualMaxDataFrameSize will be.'