This attribute indicates the total number of ATM Cell Severely
Errored Seconds (SESs) that have been counted.
In direct mapping mode, an ATM Cell SES is declared for second
intervals containing one or more Out of Cell Delineation (OCD)
defects. An OCD defect occurs when seven consecutive incorrect
HECs have been detected. An OCD defect terminates when six
consecutive correct HECs have been detected.
In PLCP mapping mode, an ATM Cell SES is declared for second
intervals containing one or more PLCP LOF defects.
Counting of uncorrectableHeaderErrors (ucErr) and
correctableHeaderErrors (cErr) is inhibited when the OCD defect
is present.