Installation guide

3-5
Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
OL-2238-03
Chapter 3 Configuring the Cisco Cable Interface
Configuring the Downstream Cable Interface
Router# show controllers cable1/0 downstream
Cable1/0 Downstream is up
Frequency=96000000, 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: 1
For EuroDOCSIS operations, a sample appears below:
Router# show controllers cable 1/0 downstream
Cable1/0 Downstream is up
Frequency 669.0000MHz, Channel Width 8MHz, 64-QAM, Symbol Rate
6.952000 Msps
FEC ITU-T J.83 Annex A, R/S Interleave I=12, J=17
Downstream channel ID: 1
Setting the MPEG Framing Format
The MPEG framing format must be compatible with DOCSIS or EuroDOCSIS specifications and your
local cable plant operations.
Tip Annex B is the DOCSIS MPEG framing format standard for North America, supported on the
Cisco uBR7111 and Cisco uBR7114 routers. Annex A is the European standard, supported on the
Cisco uBR7111E and Cisco uBR7114E routers.
Note Annex A or B framing format is automatically set when configuring the cable interface. The downstream
ports and the connected CMs on the network must be set to the same MPEG framing format and support
DOCSIS or EuroDOCSIS operations as appropriate.
The following command appears in the Cisco uBR7100 series router configuration file to designate
Annex B or Annex A operation. This command sets the downstream MPEG framing format.
CMTS01(config-if)# cable downstream annex {B}
Verifying the Downstream MPEG Framing Format
To verify the downstream MPEG framing format setting, enter the show controllers cable command for
the downstream port you have just configured. See the following example:
router# show controllers cable1/0 downstream
Cable1/0 Downstream is up
Frequency=96000000, 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
A sample output appears below for EuroDOCSIS operations:
Router# show controllers cable 1/0 downstream
Cable3/0 Downstream is up
Frequency 669.0000MHz, Channel Width 8MHz, 64-QAM, Symbol Rate
6.952000 Msps
FEC ITU-T J.83 Annex A, R/S Interleave I=12, J=17
Downstream channel ID: 0