Chapter 1 Introducing the Model DPR2320, DPR2325, EPR2320, and EPR2325 Cable Modem Gateways
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WebWizard Gscan Function
When installing a cable modem gateway, you can speed up the process by using the
WebWizard Gscan function. To access the WebWizard Gscan function, you must
first connect a PC to the cable modem. Then, using your Web Browser, you can
access the WebWizard Gscan function.
Note:
For more information on the WebWizard Gscan function, see
WebWizard
(on page 106).
Obtain Upstream Parameters
After finding a valid downstream data channel, the cable modem gateway reviews
the upstream parameters needed to perform the next stage: ranging and automatic
adjustments. The upstream parameters enable the cable modem gateway to send
data to the CMTS. When the cable modem gateway finds the correct upstream
parameters, the cable modem gateway proceeds to the ranging and automatic
adjustments stage.
If the cable modem gateway cannot find valid upstream parameters, it returns to the
scan for downstream channel stage. Then the cable modem gateway starts to scan
again at the next available channel.
Adjust Timing Offset and Power Level
After the cable modem gateway obtains its upstream parameters, it begins the
ranging and automatic adjustments stage. In this stage, the cable modem gateway
adjusts the timing offset and the power level for communicating with the CMTS.
The cable modem gateway uses MAC messages to determine the upstream channel
frequency and adjusts timing offsets to verify the synchronized timing between the
CMTS and the cable modem gateway. This process also determines the upstream
signal transmit power level from the cable modem gateway to communicate with the
CMTS.
After the cable modem gateway completes the ranging stage and registers with the
CMTS, it repeats this routine regularly to fine-tune the settings established in the
previous stages. These regular adjustments are considered routine maintenance and
do not affect normal operations of your cable modem gateway service.
Note:
If the cable modem gateway fails to achieve the proper settings when
performing ranging and automatic adjustments, it terminates the session and restarts
the initialization process at the scan for downstream channel stage.