If a critical network incident occurs, take emergency measures by following the procedures in Emergency Maintenance. A critical network incident occurs when any of the following situations happens:

• A large number of subscribers raise complaints.
• A large number of hardware failure alarms are generated in the Browse Alarms window.
• Link congestion or flow control alarms are generated in the Browse Alarms window.
• The provisioning system remains disconnected from the UPCC for over 15 minutes, or a large number of service provisioning commands fail.
• The bearer network quality deteriorates by over 5% compared with the previous day.
• The value of a key performance indicator (KPI) listed in Table 1 decreases significantly compared with the previous day. The emergency conditions provided in Table 1 are for reference only and may vary depending on your situation.