The two objects hwDot3ahEfmErrSymPeriodWindowHi and
hwDot3ahEfmErrSymPeriodWindowLo together form an unsigned 64-bit
integer representing the number of symbols over which this
threshold event is defined. This is defined as
hwDot3ahEfmErrSymPeriodWindow = ((2^32)*hwDot3ahEfmErrSymPeriodWindowHi)
+ hwDot3ahEfmErrSymPeriodWindowLo
If hwDot3ahEfmErrSymPeriodThreshold symbol errors occur within a
window of hwDot3ahEfmErrSymPeriodWindow symbols, an Event
Notification OAMPDU should be generated with an Errored Symbol
Period Event TLV indicating the threshold has been crossed in
this window.
The default value for hwDot3ahEfmErrSymPeriodWindow is the number
of symbols in one second for the underlying physical layer.