Cisco DPC2203C Installation And Operation Manual page 25

WebWizard Gscan Function
When installing a cable modem, 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 58).
Obtain Upstream Parameters
After finding a valid downstream data channel, the cable modem reviews the
upstream parameters needed to perform the next stage: ranging and automatic
adjustments. The upstream parameters enable the cable modem to send data to the
CMTS. When the cable modem finds the correct upstream parameters, the cable
modem proceeds to the ranging and automatic adjustments stage.
If the cable modem cannot find valid upstream parameters, it returns to the scan for
downstream channel stage. Then the cable modem starts to scan again at the next
available channel.
Adjust Timing Offset and Power Level
After the cable modem obtains its upstream parameters, it begins the ranging and
automatic adjustments stage. In this stage, the cable modem adjusts the timing offset
and the power level for communicating with the CMTS.
The cable modem 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. This process also determines the upstream signal transmit power
level from the cable modem to communicate with the CMTS.
After the cable modem 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 service.
Note: If the cable modem 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.
72-4017315-01 Rev B
Theory of Operation
9