Cisco Systems uBR7200 Series manual Show Cable Modem

Chapter 4 Troubleshooting the System

Understanding Show Command Responses

•The show cable flap-listand show cable modem commands now indicate when the Cisco uBR7200 series router has detected an unstable return path for a particular modem and has compensated with a power adjustment. An asterisk appears in the power adjustment field for a modem when a power adjustment has been made; an exclamation point appears when the modem has reached its maximum power transmit level and cannot increase its power level any further.

•The show controller upstream command is enhanced to display the following information on cable interfaces:

–Upstream channel utilization in minislots

–Contention slots

–Initial ranging slots

–Minislots lost due to the MAP interrupt being too late.

You can also limit your search for modem status to specific cable interfaces.

Show Cable Modem

Using Cisco IOS Release 12.0(7)XR2, Cisco IOS Release 12.1(1a)T1 or higher, the

show cable modem command includes all DOCSIS states, as well as other useful troubleshooting information such as last received upstream RF power level and maximum number of provisioned customer premises equipment.

Note DOCSIS cable modems are required to pass through successive states during registration and provisioning. Using this information, you can isolate why a cable modem is offline or unavailable.

Specific added information includes the downstream receive power ratio, downstream SNR, upstream and downstream power levels, transmit timing offset, and micro reflections in decibels.

For each upstream channel, you can obtain the following information:

•The total number of modems

•The number of active modems

•The number of registered modems

•The number of unregistered modems

•The number of offline modems.

•The time the modem went offline

•The status before the modem went offline

•The receive power before the modem went offline.

Cisco uBR7200 Series Universal Broadband Router Software Configuration Guide

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