Cisco Systems UBR10012 Activating the Upstream Scrambler, Activating Upstream Timing Adjustment

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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

To determine if upstream power adjustment is configured and activated, enter the showrunning-config

command and look for the cable interface configuration information. If upstream power adjustment is

enabled, any or all three of the continue, noise, and threshold power-adjustment entries appear in the

show running-config command output. If all three upstream power adjustments are disabled, no

power-adjustment entry appears in the showrunning-config command output.

Activating the Upstream Scrambler

The scrambler on the upstream RF carrier enables CMs on the HFC network to use built-in scrambler

circuitry for upstream data transmissions. The scrambler circuitry improves reliability of the upstream

receiver on the cable interface line card.

Caution The upstream scrambler is activated by default and should not be disabled under normal

circumstances. Disabling it can result in corrupted packets. Disable it only for prototype modems that

do not support the upstream scrambler.

To activate the upstream scrambler, use the following command in cable interface configuration mode.

The upstream scrambler is enabled by default.

Router(config-if)# cable upstream usport scrambler

To determine if the upstream scrambler is activated, enter the moresystem:running-config command

and look for the cable interface configuration information. 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 Upstream Timing Adjustment

To enable upstream timing adjustment for a specified cable interface, use one of the following commands

in cable interface configuration mode.

\Command Purpose

Router(config-if)# cable upstream usport

time-adjust continue seconds Sets the minimum timing adjustment that allows

continued ranging status. Valid values are

2to64seconds. Default = 2 seconds.

Router(config-if)# cable upstream usport

time-adjust threshold seconds Sets the timing adjustment threshold value in

seconds. Valid values are 1 to 32 seconds.

Default= 1 second.

Router(config-if)# end

Router# Returns to enable (privileged EXEC) mode.