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Cisco uBR10012 Universal Broadband Router Software Configuration Guide
OL-1520-05
Chapter 3 Configuring Cable Interface Features for the Cisco uBR10012 Router
Configuring the Downstream Cable Interface
Verifying the Downstream Helper Address
To verify the downstream helper address setting, enter the
show running-config
command and look for
cable helper-address
in the cable interface configuration information:
Router#
show running-config
Building configuration...
Current configuration:
!
interface cable5/0/0
ip address 10.254.254.254 255.0.0.0
no ip directed-broadcast
cable helper-address 192.168.1.1
no keepalive
Perform these steps if you are having difficulty with verification:
Step 1
Check the cables, upconverters, RF levels, and frequencies if the cable interfaces do not find a
downstream signal.
Step 2
Check the cables, RF levels, and upstream frequencies, and enter a
no shut
command if the
cable interfaces find a downstream signal, but not an upstream signal.
Step 3
Check the provisioning servers.
•
Ping the DHCP server using the source IP address option—the primary IP address of a cable
interface.
•
Check IP routing if the cable interfaces acquire an RF upstream and downstream lock, but do not
stay up.
Step 4
Check DHCP options and the IP address of the Time-of-Day (ToD) server:
•
Ping the ToD server using the source IP address option.
•
Check IP routing.
•
Verify that the TFTP filename is correct.
•
Verify that the TFTP file is in the correct directory on the TFTP server.
•
Ensure that the TFTP file has read privileges.
•
Ping the TFTP server using the source IP address option, and check IP routing if the cable interfaces
acquire an RF and a DHCP, but fail on ToD or TFTP.
Setting the Downstream Interleave Depth
Set the interleave depth for the downstream port on the Cisco cable interface line card. A higher
interleave depth provides more protection from bursts of noise on the HFC network; however, it
increases downstream latency.
Note
The valid values are 8, 16, 32 (default), 64, and 128.
To set the downstream interleave depth in milliseconds, use the following command in cable interface
configuration mode:
Router(config-if)#
cable downstream interleave-depth
{
8
|
16
|
32
|
64
|
128
}