An integer corresponding to the Event Time Stamp field in
the most recently transmitted Errored Frame Event TLV in
an Event Notification OAMPDU (see 57.4.3.2). This integer
is updated when a OAM:MA_DATA.request service primitive is
generated within the OAM sublayer with an OAMPDU Code
field value equal to the Event Notification code as
specified in Table 57-4 and Event TLV Type field equal to
the Errored Frame Event value as specified in Table 57-10.