Avaya CS 1000 Maintenance Manual page 51

PRI error detection
Figure 7: Frame alignment
If a loss of frame alignment condition persists for three seconds, the affected PRI loop is taken
out of service and a Red alarm (local alarm) is raised. See Figure 8: Frame alignment loss on
page 51.
If the loss of frame alignment condition clears for at least 15 seconds, the PRI is automatically
restored to service. The following DTA message is generated:
DTA021: Loss of frame alignment has persisted for 3 seconds.
Figure 8: Frame alignment loss
ISDN Primary Rate Interface Maintenance November 2011 51