Installation guide

5-18
Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
OL-2238-03
Chapter 5 Troubleshooting the System
Understanding Show Command Responses
show cable modem Command
The show cable modem command includes all DOCSIS states, and other useful troubleshooting
information such as last received upstream RF power level and maximum number of provisioned
customer premises equipment.
Note DOCSIS CMs are required to pass through successive states during registration and provisioning. Using
this information, you can isolate why a CM 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:
• Total number of modem(s)
• Number of active modem(s)
• Number of registered modem(s)
• Number of unregistered modem(s)
• Number of offline modem(s)
• Time the modem(s) went offline
• Status before the modem(s) went offline
• Receive power before the modem(s) went offline
Sample show cable modem command output follows:
Router# show cable modem
Interface Prim Online Timing Rec QoS CPE IP address MAC address
Sid State Offset Power
Cable1/0/U0 1 online 2257 0.00 3 0 10.30.128.142 0090.8330.0217
Cable1/0/U0 2 online 2262 *-0.50 3 0 10.30.128.145 0090.8330.020f
Cable1/0/U0 3 online 2260 0.25 3 0 10.30.128.146 0090.8330.0211
Cable1/0/U0 4 online 2256 *0.75 3 0 10.30.128.143 0090.8330.0216
Cable1/0/U0 5 online 2265 *0.50 3 0 10.30.128.140 0090.8330.0214
Cable1/0/U0 6 online 2256 0.00 3 0 10.30.128.141 0090.8330.0215
Cable1/0/U0 7 online 4138 !-1.00 3 1 10.30.128.182 0050.7366.124d
Cable1/0/U0 8 online 4142 !-3.25 3 1 10.30.128.164 0050.7366.1245
Cable1/0/U0 9 online 4141 !-3.00 3 1 10.30.128.185 0050.7366.17e3
Cable1/0/U0 10 online 4142 !-2.75 3 0 10.30.128.181 0050.7366.17ab
Cable1/0/U0 11 online 4142 !-3.25 3 1 10.30.128.169 0050.7366.17ef
The output from the show cable modem command indicates when the Cisco uBR7100 series CMTS has
detected an unstable return path for a particular CM and has compensated with a power adjustment. An
asterisk (*) in the power adjustment field for a CM indicates that a power adjustment has been made. An
exclamation point (!) indicates that the CM has reached its maximum power transmit level and cannot
increase its power level any further
.
Columns are described below:
• prim Sid column reveals the primary (lifeline) service identifier assigned to the CM.
• SID column is the service identifier.
• Online State column reveals the state of the modem; values include:
– offline—CM considered offline.