This packs both the alarm type and the affected interface into a single identifier value, and critically the same AlarmId value is reused for both the raise event and its later clear event, letting a management system pair up a problem-started notification with its matching problem-resolved notification. Without this pairing, an NMS would have no reliable way to compute how long a given alarm condition, say a specific interface's LOS, actually persisted. A management station correlating trap history would match a raised AlarmId of, say, 1032 against a later clear trap carrying that same 1032 to compute the exact outage duration.