The number of frames over which the threshold is defined.
The default value of the window is the number of minimum size
Ethernet frames that can be received over the physical layer
in one second.
If cdot3OamErrFramePeriodThreshold frame errors occur within a
window of cdot3OamErrFramePeriodWindow frames, an Event
Notification OAMPDU should be generated with an Errored Frame
Period Event TLV indicating the threshold has been crossed in
this window.