Troubleshooting guide

Troubleshooting the CMTS
4-45
Initial maintenance @ Time T1
Station maintenance
Init maintenance @ Time T2
The Ins and Flap counters in the flap list are incremented whenever T2 – T1 < N
where N is the insertion-time parameter configured using the cable flap-list
insertion-time command. The default value for this parameter is TBD seconds.
Use the following cause or symptom observations to interpret flap list activity and
solve CM problems:
Table 4-2 Troubleshooting CM Problems
Cause or Symptom Problem
Subscriber CM shows a lot of flap list
activity
CM is having communication problems with
the BSR.
Subscriber CM shows little or no flap
list activity.
The CM is communicating with the BSR
effectively, however there is still a problem.
The problem can be isolated to the
subscriber’s CPE computer equipment or
the CM connection.
Ten percent of the CMs in the flap list
show a lot of activity.
These CMs are most likely having
difficulties communicating with the BSR.
CMs have a lot of power adjustment
(P-Adj) errors.
CMs have problems with their physical
upstream paths or in-home wiring problems.
Use corresponding CMs on the same
physical upstream port interface with similar
flap list statistics to quickly resolve problems
outside the cable plant to a particular node
or geographic location.
All CMs are incrementing the insertion
at the same time.
There is a provisioning server failure.
A CM has more than 50 power
adjustments per day.
The CM has a suspect upstream path.
Corresponding CMs on the same physical
upstream port interface with similar flap list
statistics can be used to quickly resolve
problems outside the cable plant to a
particular node or geographic location.