System information

Configuring the CMTS
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Activating the Scrambler on the Upstream Channel
The scrambler on the upstream channel enables CMs on the HFC network to use
built-in scrambler circuitry for upstream data transmissions. The scrambler circuitry
improves BSR upstream receiver. The upstream scrambler is enabled by default and
should not be disabled.
If you must re-enable the upstream scrambler, use the cable upstream scrambler
command in Interface Configuration mode, as shown below:
MOT(config-if)#cable upstream <NUM> scrambler
where:
NUM is the upstream port number.
To disable the upstream scrambler, use the no cable upstream scrambler command
in Interface Configuration mode, as shown below:
MOT(config-if)#no cable upstream <NUM> scrambler
Enabling Pre-equalization
Use the cable upstream pre-equalization command to enable the pre-equalization
adjustment function on the upstream port, which includes sending pre-equalization
coefficients in a ranging response to a CM to compensate for impairment over the
transmission line in Interface Configuration mode, as shown below:
MOT(config-if)#cable upstream <NUM> pre-equalization
Note: Scrambler must be enabled for normal operation. Disable only for
prototype modems that do not support scrambler.
Note: Not all CMs support the pre-equalization adjustment. If you enable the
pre-equalization adjustment for an upstream port and the CM does not
support this adjustment, the cable interface may not receive valid upstream
data from the CM.