In most cases, complete frames are available for decoding. However, the protocol analyzer will work with frames that have been truncated. This feature can be very handy when frames tend to be long and only the protocol information at the start of each is of interest but not the "data" that follow. Such truncation often occurs when frames are imported from some other source.
As a reminder, the values that pertain to truncated frames are:
inbytLeftInAvailableLayer
inbytLeftInFullLayer
inbytTruncated
Whenever you write a method that directly accesses the abytLayer array, we urge you to consistently use the relevant values (especially inbytLeftInAvailableLayer) to verify that what you want to access is really there before grabbing it.