Cisco Broadband Cable, Reference Manual

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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
cable spectrum-group hop period
To change the minimum time between frequency hops, use the cable spectrum-group hop period
command in global configuration mode. To reset the frequency hop interval for this spectrum group to
its default value, use the
no form of this command.
cable spectrum-group groupnum hop period seconds
no cable spectrum-group groupnum hop period
Syntax Description
Defaults Before Cisco IOS Release 12.2(15)BC1: 25 seconds
Cisco IOS Release 12.2(15)BC1 and later releases: 20 seconds when N+1 HCCP redundancy is not
configured, and 15 seconds when N+1 HCCP redundancy is configured on the cable interface
Command Modes Global configuration
Command History
Usage Guidelines
The cable spectrum-group hop period command defines the minimum amount of time that must pass
between upstream frequency hops. If ingress noise becomes excessive on a particular upstream, you can
set this time period to a smaller value, so as to allow frequency hopping to continue more rapidly until a
clear channel is found. Conversely, if the problem appears to be a transient condition, such as a defective CM
generating a large volume of errored packets, this time period can be increased to a larger value, so as to avoid
excessive frequency hopping by allowing more time between frequency hops.
groupnum Spectrum group number. Valid values are from 1 to 32, or from 1 to 40,
depending on the Cisco IOS software release.
seconds Specifies the frequency-hop time period in seconds. Valid values are
from 1 to 3600 seconds (before Cisco IOS Release 12.2(8)BC1), or
from 1 to 300 seconds (Cisco IOS Release 12.2(8)BC1 or later).
Release Modification
12.1 T This command was introduced.
12.1(7)CX1 The default hop period was changed from 300 seconds to 25 seconds to
accommodate the new spectrum management features for the Cisco uBR-
MC16S spectrum management card.
12.2(8)BC1 The maximum frequency-hop time period was changed from 3600 to 300
seconds.
12.2(15)BC1 The default hop period was changed from 25 seconds to 20 seconds when
N+1 HCCP redundancy is not configured on the cable interface, and changed
to 15 seconds when N+1 HCCP redundancy is configured.
12.2(15)BC2 The maximum number of spectrum groups was increased from 32 to 40
groups per router.