A read-write Unsigned32 setting the number of Severely Errored Seconds permitted within a one-hour operational window before the p2mpSuSevErrSecAlarmTrap fires. Because SES represents genuinely serious per-second impairment, this hourly cap gives an admin an automatic escalation point distinct from the more lenient plain-ES alarm. For example, a link that regularly accumulates a handful of Severely Errored Seconds due to weather might have p2mpSuLink1HrSESAlarmThresh tuned higher than default to avoid nuisance traps while still catching genuinely serious degradation.