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Cisco Broadband Cable Command Reference Guide
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Chapter 2 Cisco CMTS Configuration Commands
cable flap-list miss-threshold
cable flap-list miss-threshold
To set the miss threshold for recording a flap-list event, use the
cable flap-list miss-threshold
command
in global configuration mode. To disable this function, use the
no
form of this command.
cable flap-list miss-threshold
misses
no cable flap-list miss-threshold
Syntax Description
Defaults
6
Command Modes
Global configuration
Command History
Usage Guidelines
In a DOCSIS network, the CMTS regularly sends out MAC-layer keepalive messages, known as station
maintenance messages, to each CM that is online. If a CM does not respond to a station maintenance
message, the CMTS repeats sending these messages either until the CM responds or the CMTS reaches
the maximum allowable number of messages that can be sent.
The
cable flap-list miss-threshold
command specifies how many consecutive station maintenance
messages can be missed before the cable modem is placed in the flap list. A miss occurs when a CM does
not reply to a station maintenance message.
Note
Station maintenance messages are occasionally lost due to noise or congestion in a typical DOCSIS
network, with a loss rate of approximately 8 percent considered nominal. A higher miss rate can indicate
RF plant problems, such as intermittent upstream problems, fiber laser clipping, or common-path
distortion.
Examples
The following example shows how to set the miss threshold to 5:
Router(config)#
cable flap-list miss-threshold 5
misses
Specifies the number of consecutive MAC-layer keepalive (Station
Maintenance) that can be missed before a CM is placed in the flap list.
The valid range is 1 to 12, with a default of 6.
Release
Modification
12.1 T
This command was introduced.
