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Cisco uBR905 Router Hardware Installation Guide
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Chapter 1
Product Overview
Functional Overview
download its DOCSIS configuration file. Cisco IOS images and Cisco IOS configuration files must
also be prepared for subscribers who are purchasing services that require new software images and
advanced configurations.
Note
The CMTS uses the router’s unique MAC address for the cable interface to ensure
that the router downloads only the files appropriate for the levels of service that
have been purchased.
•
If DHCP is also being used to provision the IP addresses used by the CPE devices at the subscriber’s
site, the DHCP server must be able to respond to those requests as well.
•
The CMTS system administrator must ensure that appropriate databases are updated to activate and
support the new subscriber account in the provisioning, billing, and network management systems
in place for your network after each router is registered with the CMTS.
•
The following files should be prepared and available on the TFTP server:
–
DOCSIS configuration file—This is required for every installation. The DOCSIS configuration
file specifies the DOCSIS-mandated parameters, such as upstream and downstream
frequencies, as well as optional features, such as whether to download a new software image
or a Cisco IOS configuration file.
–
Cisco IOS image—If upgrading to a Cisco IOS image different from the factory default, that
image must be specified in the router’s DOCSIS configuration file and available on a TFTP
server that is accessible through the cable interface.
–
Cisco IOS configuration file—Unless the network administrator at the subscriber’s site is
manually configuring the Cisco uBR905 router through its command-line interface, a
Cisco IOS configuration file must be prepared that specifies the routing parameters required to
route data between the cable and serial interfaces. This file can specify any other optional
features that are desired. It must be made available on a TFTP server that is accessible through
the cable interface.
Upgrading the Software Image
When Cisco IOS images are updated to new releases, the service provider can download them as needed
to Cisco uBR905 routers installed in the field (based on the software licenses purchased). See the
release notes for the router (listed in the “Related Documentation” section on page xi) for a complete
list of features and Cisco IOS images that are currently supported.
Service providers can use the router’s Media Access Controller (MAC) address to uniquely identify
each particular router in the field. The CMTS uses this value to download the proper DOCSIS
configuration file to the router before it begins operation.
The DOCSIS configuration file can also contain the name of the software image that the router should
be running. If necessary, the CMTS can also download the proper software image to the router and force
it to reboot using the new image.
The download of the DOCSIS configuration file usually takes only a few seconds and is done every time
the Cisco uBR905 router reboots. The download of the software image can take several minutes to
complete, during which time network connectivity is not available. However, the software image must
be downloaded only once, until the subscriber needs to be updated with a new or updated image.
See the Cisco uBR905 Cable Access Router Software Configuration Guide for a description on how to
download a software image and configuration file to a Cisco uBR905 router installed in the field.
