Cisco GoQAM, Installation And Operation Manual

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Troubleshooting Alarm Messages
4004834 Rev D 141
“Session xxx
data error”
where xxx is a
number from
0 to 991
Minor The data flow for the session is less than
or greater than what has been defined by
the DNCS for the session indicating one
of the following underflow or overflow
conditions:
 Cause Code 1-Underflow-The session
data rate for the session drops to 0
(zero) or is less than expected.
Important: The session rate dropping to 0
(zero) triggers an underflow alarm, but is
not the result of a loss of signal condition.
When a loss of signal occurs, the
underflow alarm is not reported. This
prevents the system from being
overwhelmed with a large number of
session data alarms. Alarms that occur as
a result of higher level alarms are not
reported.

Cause Code 2-Overflow-The data rate
for this session exceeds the
provisioned data rate.

Cause Code 3 - PID enable error - A
packet identifier (PID) that should be
enabled is not enabled in the GoQAM
modulator.

Cause Code 6 - Continuity error - This
alarm identifies the specific session on
which the Input Port (1-4) continuity
error alarm occurred.

Cause Code 8 - Excess glue frame
events - Glue frames prevent
macroblocking. Excess glue frame
events indicate that the associated
output port is receiving too much
data. When the MPEG engine in the
GoQAM nears full output capacity, it
begins to selectively choose video
PIDs on which it will issue a “freeze
frame” code in the MPEG video
stream for that program and will drop
the video packets for that session
momentarily. If this alarm occurs
frequently, it is a signal that the
output QAM carrying that session
contains too much data.

Verify and correct any
session setup
problems including
the session rate target
value. If session data is
correct, data may be
corrupted because of
hardware problems.
Note: Select data rates
that you believe the
program should not
exceed.

For the overflow
condition, teardown,
rebuild, and then
restart the session
using a higher
bandwidth.
 Run the Doctor Report
on the DNCS, and
examine the report for
any network
connectivity issues or
indications of loss of
services.

Contact Cisco Services

If this alarm occurs
with this Cause Code
and then quickly
clears, it is not a cause
for concern.
 Check the content of
the input stream using
an MPEG analyzer.

Contact Cisco Services
 Reallocate the session
from the QAM that
appears to contain too
much data to another
QAM on the same
GoQAM modulator or
to another GoQAM
modulator.