Reduced Bit Rate threshold in bits per second that is needed
for generating a major alarm and/or AIS. If the threshold
for the interface is greater than the maximum value
reportable by this object then this object should report its
maximum value (4,294,967,295) and
ethIfSrcReducedBitRateHighThreshold must be used to set or
report the threshold value. A value of 0 disables the
reduced bit rate detection.