Specifications

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Cisco Cable Modem Termination System Feature Guide
0L-1467-02
Chapter 3 Spectrum Management for the Cisco Cable Modem Termination System
Configuration Tasks
Verifying the Spectrum Management Configuration
Step 1 To check the value of the settings you have entered, enter the show running-config command in
privileged EXEC mode at the Router# prompt:
Router# show running-config
To review changes you make to the configuration, use the show startup-config command in privileged
EXEC mode to display the information stored in NVRAM.
Step 4
Router(config-if)# cable upstream n
threshold cnr-profile1 threshold1-in-dB
cnr-profile2 threshold2-in-dB corr-fec
fec-corrected uncorr-fec fec-uncorrected
(Optional) Specifies the CNR threshold and FEC values for the
upstream and its two modulation profiles.
n = upstream number on cable modem slot (on the
Cisco uBR-MC16S, upstream port numbers are 0–5)
cnr-profile1 threshold1-in-dB = CNR threshold for the primary
modulation profile (5-35 dB, with a default of 25)
cnr-profile2 threshold1-in-dB = CNR threshold for the
secondary modulation profile (5-35 dB, must be less than that
for the primary modulation profile, with a default of 15)
corr-fec fec-corrected = FEC corrected threshold as a
percentage of total packets on the upstream (3-50%, with a
default of 3%)
uncorr-fec fec-uncorrected = FEC uncorrected threshold as a
percentage of total packets on the upstream (1–10%, with a
default of 1%)
Step 5
Router(config-if)# cable upstream n
channel-width width1 width2
(Optional) Specifies the range of channel widths to scan when
ingress noise conditions require changing the channel width.
channel-width width1 width2 = the range of channel widths.
Valid values are 200000 Hz (160 kilosymbols per second
[ksps]), 400000 Hz (320 ksps), 800000 Hz (640 ksps), 1600000
Hz (1280 ksps), and 3200000 Hz (2560 ksps), where width1
specifies the default upstream channel width, and width2
specifies the last allowable (minimum) channel width; width2
must be smaller than width1.
Note The channel width starts at the primary channel and
decreases in half until it hits the secondary channel
width. For example, cable upstream 0 channel-width
3200000 400000 means that channel width starts with
a 3.2 MHz wide channel, then moves to 1.6 MHz, then
.8 MHz, then .4 MHz.
The default is a single channel width of 1600000 Hz.
Step 6
Router(config-if)# exit
Exits back to the configuration mode.
Command Purpose