Verilink NCC 2130 (880-503285-001) Product Manual - Manual (Page 46)

Diagnostics
5-4 Verilink NCC 2130 User Manual
Table 5-1 Diagnostic Menu Status Messages
Diagnostic
Commands
There are twelve command options available on the NCC 2130
Diagnostics Menu.
Table 5-2 lists all of these commands in right
to left order:
Drawings illustrating the various loopbacks can be found in the
manual
AS2000, The Basics .
Message Meaning
ALARM Yellow Alarm (RAI) —The CSU is receiving a Remote Alarm Indication Signal on the
port. This signal is sent by a device in a red alarm condition, such as AIS, LOS or LOF.
FRAME LOSS Out Of Frame (OOF) —The CSU does not detect a valid framed signal on the port. If
pulses are also present. Can indicate receipt of unframed all ones—Alarm Indication
Signal (AIS)—which is often used as a Keep Alive signal on T1 circuits.
SIGNAL LOSS Loss Of Signal (LOS) —The CSU does not detect any pulses on the port. This is the
worst possible alarm condition on a T1 port. Ignore other alarms and resolve the
cause of the LOS first. In the case of a DTE port reporting LOS, it means the LOS
option is configured to expect RTS or DTR from the DTE and that signal is not
present.
CRC ERRORS Cyclic Redundancy Check errors (CRC-6) —the CSU detects errors using the CRC-6
feature of ESF framing. Applies only to T1 circuits using ESF framing.
BPV The CSU is detecting bipolar violations on the port. Two or more pulses in a row were
of the same polarity, violating the Alternating Mark Inversion requirement.
EXT CLK LOSS The CSU is configured to use an external clock signal and that signal is not detected.
PULSES Not an alarm condition. The CSU does see valid pulses on the port. PULSES should
always be displayed on the DTE side of the menu.