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Cisco Broadband Cable Command Reference Guide
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Chapter 2 Cisco CMTS Configuration Commands
cable spectrum-group hop period
On the Cisco uBR-MC1xC cards, the maximum recommended hop period is 20 seconds. On the
Cisco uBR-MC16S and Cisco uBR-MC5X20S/U cards, the minimum recommended hop period is 25
seconds and the maximum recommended hop period is 35 seconds.
In Cisco IOS Release 12.2(15)BC2, the Cisco CMTS adaptively increases the hop period from the user-
defined value to the maximum value (300 seconds) whenever an upstream does not currently have any
CMs ranging on it, so as to avoid unnecessary frequency hopping. The user-defined value is restored
when a CM starts ranging on the upstream.
Note
The hop period should be set to at least 25 seconds on the Cisco uBR-MC16S and Cisco uBR-
MC5X20S/U cards so that transient network problems that are unrelated to ingress noise do not generate
unnecessary frequency hops.
Examples
The following example shows how to change the minimum frequency-hop interval to 60 seconds. This
means that frequency hops for this spectrum group cannot occur more quickly than once every 60
seconds, even if other characteristics, such as exceeding the CNR or FEC threshold values, would
normally trigger the hop.
router#
configure terminal
router(config)#
cable spectrum-group 1 hop period 60
router(config)#
Related Commands
Command
Description
cable modulation-
profile
Creates a cable modulation profile.
cable spectrum-group
hop threshold
Specifies a hop threshold for a cable spectrum group.
cable upstream
channel-width
Configures an upstream for a range of allowable channel widths.
cable upstream
modulation-profile
Configures an upstream for one modulation profile (static profile) or two
modulation profiles (Dynamic Upstream Modulation).
show cable hop
Displays the current hop period and threshold for an upstream, along with
other statistics.