Your last CSU alarm post would indicate the problem is with your carrier. The 2000 on shows a Yellow alarm. You could double check with one of the guru’s in the T1 forum.

NI
AIS-Active
Out Of Frame - Active
Red - Active

T1
Yellow - Active


Network Interface Alarms

AIS Alarm Unframed all-ones received at NI
Out of Frame No framing pattern sync at NI
Red Alarm LOS (loss of signal)/out of frame (OOF) causing red alarm at NI


T1 terminal Interface Alarms

Yellow Alarm Receiving yellow alarm pattern from T1


JimmyV

"Well informed people know it is impossible to transmit the voice over wires. Even if it were, it would be of no practical value" Boston Post, 1865