Cisco SR2016T-NA Reference Manual page 249

Chapter 2 Cisco CMTS Configuration Commands
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.
Syntax Description groupnum
seconds
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 Release
12.1 T
12.1(7)CX1
12.2(8)BC1
12.2(15)BC1
12.2(15)BC2
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.
OL-1581-08
cable spectrum-group groupnum hop period seconds
no cable spectrum-group groupnum hop period
Modification
This command was introduced.
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.
The maximum frequency-hop time period was changed from 3600 to 300
seconds.
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.
The maximum number of spectrum groups was increased from 32 to 40
groups per router.
Spectrum group number. Valid values are from 1 to 32, or from 1 to 40,
depending on the Cisco IOS software release.
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).
Cisco Broadband Cable Command Reference Guide
cable spectrum-group hop period
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