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Cisco uBR10012 Universal Broadband Router Software Configuration Guide
OL-1520-05
Chapter3 Configuring Cable Interface Features for the CiscouBR10012Router
Configuring the Upstream Cable Interface
Activating Upstream Forward Error Correction
The CiscouBR10000series CMTS uses forward error correction (FEC) to attempt to correct any
upstream data that might have been corrupted. When FEC is activated, all CMs on the network also
activate FEC.
Note Although upstream FEC is an option, Cisco recommends that you use upstream FEC. FEC is
activated by default and should not be disabled.
To activate the upstream forward error correction and to enable FEC, use the following command in
cable interface configuration mode.
Router(config-if)# cable upstream usport fec

Verifying Upstream FEC

To verify whether FEC is activated or deactivated, enter the more system:running-config command and
look for the cable interface configuration information. If FEC is enabled, an FEC entry appears in the
showrunning-config command output. If FEC is disabled, no FEC entry appears in the output.
Perform these steps if you are having difficulty with verification:
Step1 Ensure that the cable connections are not loose or disconnected.
Step2 Ensure that the cable interface line card is firmly seated in its chassis slot.
Step3 Ensure that the captive installation screws are tight.
Step4 Verify that you have entered the correct slot and port numbers.
Step5 Verify that you selected a valid frequency for your router.
Activating the Upstream Ports
Each upstream port must be activated to enable upstream data transmission from the CMs on the HFC
network to the CiscouBR10000series CMTS.
Note The upstream cable interface does not operate until you either set a fixed upstream frequency or create
and configure a spectrum group. Refer to the Setting the Upstream Frequencysection on page20 for
details.
To activate the upstream ports, use the following commands in global configuration mode.
Command Purpose
Step1 Router(config)# interface cable slot/port Specifies a cable interface and enters cable interface
configuration mode.
Step2 Router(config-if)# no cable upstream usport shutdown Enables upstream data traffic.