Alarms are classified depending on their impact on system operation:

• Major alarms identify failures that cause a critical degradation of service. These alarms require immediate attention.

• Minor alarms identify failures that cause some service degradation but do not render a crucial portion of the system inoperable. Minor alarms require attention. However, a minor alarm typically affects only a few trunks, stations, or a single feature.

• Warning alarms identify failures that cause no significant degradation of service or equipment failures external to the switch. These failures are not reported to INADS or to the attendant console.

• On-board problems originate in the circuitry on the alarmed media module or circuit pack.

• Off-board problems originate in a process or component that is external to the Media Module or circuit pack.