This read-only PerfCounter64 counts Severely Errored Seconds for this flow point's Ethernet OAM session during the bin. It is a standard OAM quality indicator, so a rising SES count tells an administrator the link is experiencing bursts of heavy errors severe enough to count each affected second, not just isolated bit errors. For example, an SLA review comparing cmOAMFlowPointStatsSES against the customer's contracted availability target would use this counter to check for breach-worthy error bursts during the billing period.