Installation guide

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Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
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Chapter 3 Configuring the Cisco Cable Interface
Setting and Viewing Concatenation
To configure the above modulation profile at the CMTS, use the following commands:
Create a new qpsk modulation profile template m with all default parameters, except the “short grant”
profile which has special parameters as given below:
cmts(config)# cable modulation-profile m qpsk
cmts(config)# cable modulation-profile m short 2 52 16 8 qpsk scrambler 152 diff 72
shortened uw8
Configure upstream port n on a given interface to use minislot size of 8 ticks and above modulation
profile template m:
cmts(config-if)# cable upstream n minislot-size 8
cmts(config-if)# cable upstream n modulation-profile m
Setting and Viewing Concatenation
To turn concatenation off or on from the CMTS, use the cable upstream concatenation interface
configuration command. To turn off concatenation from the default state of on, use the no form of this
command.
cable upstream n concatenation
no cable upstream n concatenation
Note Concatenation is part of DOCSIS 1.0 extension support. Concatenation must be supported at both the
CMTS and the CM. When enabled on both the CMTS and the CM, the CMTS can receive a concatenated
burst of multiple MAC frames from the CM.
Setting Concatenation
Tip Concatenation is enabled by default.
Caution Turning off concatenation instructs the CM that the CMTS does not want the CM to concatenate. It is
actually up to the CM not to concatenate. If the CM concatenates even after the no cable upstream
number concatenation interface command is issued, the CM might concatenate incorrectly. Such a CM
is considered noncompliant.
Command Purpose
Step 1
Router(config-if)# no cable upstream n concatenation
Turns off concatenation on the specified channel.
Step 2
Router(config-if)# cable upstream n concatenation
Turns on concatenation on the specified channel.