Installation guide

3-4
Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
OL-2238-03
Chapter 3 Configuring the Cisco Cable Interface
Configuring the Downstream Cable Interface
FEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Downstream channel ID: 0
Then enter the show controllers cable command, which also displays the center frequency, along with
the power levels and whether the integrated upconverter is enabled. The following is a typical display
when these values have been correctly configured:
ubr7100# show controllers cable1/0
Interface Cable1/0
Hardware is IMC11
BCM3210 revision=0x56B2
Cable1/0 Upconverter is Enabled Output is Enabled
Model: 74-2094-01 Serial Number: 0WAV04480010 CLEI Code: CLEI#
HW Rev: PC2D0107 SW Rev: 007, NVRAM Rev: 006 ECI number 123456
Downstream Frequency 525.0000 MHz
IF Power 0.3 dBmv RF Power 51.0 dBmv
...
If the center frequency has not been configured, the frequency is shown as “not set” as shown in the
following example:
ubr7100# show controllers cable1/0 downstream
Cable1/0 Downstream is up
Frequency is not set. Channel Width 6 MHz, 64-QAM, Symbol Rate 5.056941 Msps
FEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Downstream channel ID: 0
If you are having trouble, make sure the cable connections are not loose or disconnected, and that you
have calculated and entered the center frequency for your router accurately.
Setting the Downstream Channel ID
To assign a numeric channel ID to the downstream port on the Cisco cable modem card, use the following
command in cable interface configuration mode. Acceptable range is 0 to 255.
CMTS01(config-if)# cable downstream channel-id id
Note The cable downstream channel-id command must be used with the following command:
cable downstream frequency 54000000-1000000000 broadcast frequency - h
The commands are used in instances where you want to send multiple downstream frequencies to a
single region that contains CMs that can only connect to upstream ports on the same cable modem card.
You must configure unique channel IDs for each downstream that any CM is capable of receiving. The
downstream frequency setting must match the setting on the upconverter.
Caution After defining unique downstream IDs, test the CMs for correct operation. Cisco recommends when
using this feature that you re-test each subsequent software release of CM code to verify correct
operation, and ensure reasonable acquisition time for new installations. Failure to use these commands
in conjunction or to test the involved CMs can result in customer service outages of indefinite duration.
Verifying the Downstream Channel ID
To verify the downstream channel ID, enter the show controllers cable command for the downstream
port you have just configured. See the following example: