Download Cisco MC16S Specifications

Chapter 3
Spectrum Management for the Cisco Cable Modem Termination System
Configuration Examples
Router(config)# cable
scrambler 152 no-diff
Router(config)# cable
scrambler 152 no-diff
Router(config)# cable
152 no-diff 144 fixed
Router(config)# cable
152 no-diff 160 fixed
Note
modulation-profile
256 fixed uw16
modulation-profile
256 fixed uw16
modulation-profile
uw16
modulation-profile
uw16
2 initial 5 34 0 48 16qam
2 station 5 34 0 48 16qam
2 short 5 75 6 8 16qam scrambler
2 long 8 220 0 8 16qam scrambler
When using DOCSIS concatenation with a 16-QAM or mixed symbol rate, configure the CMTS for
Unique Word 16 (“uw16”) in the preamble for both short and long data burst profiles.
Add the cable upstream port-number modulation-profile primary profile-number secondary
profile-number command to the appropriate interfaces. In this example, modulation-profile 2 is for
QAM-16 modulation and profile 1 is for QPSK modulation.
Router# configure terminal
Router(config)# interface Cable6/0
Router(config-if)# cable upstream 0 modulation-profile 2 1
Input Power Level Examples
In the following example, the modem transmit power at 24.8 MHz is adjusted upstream by 1 dBmV and
the modem transmit power at 28.0 MHz is adjusted upstream by 2 dBmV.
CMTS01(config)# cable spectrum-group 1 frequency 21600000
CMTS01(config)# cable spectrum-group 1 frequency 24800000 1
CMTS01(config)# cable spectrum-group 1 frequency 28000000 2
Advanced Spectrum Management Configuration Examples
This section provides the following typical configurations:
•
Advanced Spectrum Management for the Cisco uBR7200 Series Router, page 3-66
•
Advanced Spectrum Management for the Cisco uBR10012 Router, page 3-69
Advanced Spectrum Management for the Cisco uBR7200 Series Router
This section provides a typical configuration example for a Cisco uBR7200 series router using the
Cisco uBR-MC16S cable interface line card. This configuration does the following:
•
Creates three spectrum groups with different frequency bands, hop periods, and hop thresholds.
•
Creates two upstream modulation profiles, one for QPSK operation and one for QAM-16 operation,
by specifying the parameters for each burst type.
Creates two upstream modulation profiles, one for QPSK operation and one for mixed
QPSK/QAM-16 operation, using the default profile options (qpsk and mix).
• Configures one upstream (port 5) on cable interface 3/0 to use spectrum group 3.
• Configures the upstreams with the primary modulation profile set to mixed QPSK/QAM-16
operation and the secondary modulation profile set for QPSK operation.
•
Cisco Cable Modem Termination System Feature Guide
3-66
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