Major alarms, Minor alarms, Major alarms -4 minor alarms -4 – Verilink HDM 2182 (880-502925-001) Product Manual User Manual

Page 74

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Troubleshooting

6-4

Verilink HDM 2182 User Manual

Alarm Indication Signal Second (AISS)—A second when the
CSU receives an unframed all-ones Alarm Indication Signal
(AIS) from the network.

Loss of Frame Second (LOFS)—A LOFS is the total number of
seconds that the CSU was in the Loss of Frame (LOF) state.

Loss of Signal Second (LOSS)—A LOSS is a second during
which the CSU is in a Loss of Signal (LOS) state.

Severely Errored Framing Second (SEFS)—the second in
which two or more framing bit errors occur within a 3-
millisecond period.

Major Alarms

A major alarm indicates a condition where performance is seriously
affected, for example, a T3 line failure. It prevents data from being
reliably transmitted across the circuit. When a major alarm is
declared, the HDM 2182 module sends a message to the Craft
interface and Node Manager (if used), lights the appropriate LED
indicator, and trips the alarm relay (if connected). The following
error conditions must persist for at least one second for a major
alarm to be declared:

C-bit Severely Errored Seconds (CSES)—A CSES is a second
with 44 or more CCVs or one or more Out of Frame defects or a
detected incoming AIS.

P-bit Severely Errored Seconds (PSES)—A PSES is a second
with 44 or more PCVs or one or more Out of Frame defects or a
detected incoming AIS. This gauge is not increased when UASs
are counted.

Local Unavailable Second (LUAS)—An unvailable second
during which the local DS3 port is unable to receive or
transmit traffic.

Line Severely Errored Second (LSES)—A second during which
the port was (at any instance during the second) in the AIS
state.

Minor Alarms

The following error conditions do not affect traffic along the DS3
line. They generate a minor alarm:

Power Supply Missing (in redundant power supply
configurations)—This alarm indicates that one of the
redundant power supplies has failed.

Remote Alarm Indication (RAI)—This alarm indicates that the
remote end is in a state of alarm. A Remote Alarm or Remote
Alarm Indication is the alarm a receiving channel bank or
multiplexer sends to the other end of the circuit when it
detects a Loss Of Signal or Loss Of Frame. There is a 2- to 3-

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