Troubleshooting guide

BSR Troubleshooting Guide
4-44
Interpreting Flap List Statistics
This section describes how to interpret flap list statistics in order to troubleshoot
the cable network
CM activity follows the sequence below.
• Power-on
• Initial maintenance
• Station maintenance
• Power-off
The initial link insertion is followed by a keepalive loop between the BSR and CM
and is called station maintenance. When the link is broken, initial maintenance is
repeated to re-establish the link.
Ins The Insertions Link process is used by a CM to perform an initial
maintenance procedure to establish a connection with the BSR.
The Ins column is the flapping CM’s (re) insertion count and
indicates the number of times the a CM starts and inserts into the
network in an abnormal way. An abnormality is detected when the
time between link re-establishment attempts is less than the
user-configurable parameter. This function can identify potential
problems in the downstream interface such as incorrectly
provisioned CMs repeatedly trying to reestablish a link.
Hit The Hit and Miss column fields detect the intermittent upstream; the
keepalive hits versus misses is the number of times CMs do not
respond to the MAC layer keepalive messages. If there are a
number of misses, this points to a potential upstream problem.
Miss
P-Adj The Power Adjustment column field shows power adjustment
statistics during station maintenance polling. This column indicates
the number of times the BSR tells a CM to adjust the transmit
power more than the configured threshold. If constant power
adjustments are detected, an amplifier problem is usually the
cause. The source of failure is found by viewing CMs either in front
or behind various amplifiers.
Flap Time Indicates the most recent time a flap has occured for a particular
CM.
Table 4-1 Flap List Command Output Identifications
Field Identification