Installation guide

3-9
Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
OL-2238-03
Chapter 3 Configuring the Cisco Cable Interface
Configuring the Upstream Cable Interface
Verifying Downstream Rate Limiting
To determine if downstream rate limiting is configured and activated, enter the show running-config
command and look for the cable interface configuration information. If downstream rate limiting is
configured and enabled, a rate limiting entry displays in the output. If downstream rate limiting is
disabled, no rate limiting entry displays.
CMTS01# show running-config
Building configuration...
Current configuration:
!
interface Cable1/0
ip address 10.254.254.254 255.0.0.0
no ip directed-broadcast
cable helper-address 192.168.1.1
no keepalive
cable downstream rate-limit token-bucket shaping
cable downstream annex B
cable downstream modulation 64qam
Perform these steps if you are having difficulty with verification:
1. Ensure the cable connections are not loose or disconnected.
2. Ensure the cable modem card is firmly seated in its chassis slot.
3. Ensure the captive installation screws are tight.
4. Verify that you have entered the correct slot and port numbers
5. Verify that you selected the default if you are not certain about the modulation rate needed.
6. Verify the downstream carrier is active using the cable downstream if-output command.
Configuring the Upstream Cable Interface
Upstream cable interface commands configure the frequency and input power level of the upstream
signal, in addition to error detection and correction of the upstream signal. The configuration of the
upstream cable interface depends on the characteristics of your cable plant.
Perform the following tasks to configure the upstream cable interface.
Note For some of these tasks, default values are adequate to configure the device.
• “Setting the Upstream Frequency” section on page 3-10
• “Setting the Upstream Channel Width” section on page 3-11
• “Setting the Upstream Input Power Level” section on page 3-13
• “Activating Upstream Admission Control” section on page 3-14
• “Activating Upstream Forward Error Correction (FEC)” section on page 3-14
• “Specifying Upstream Minislot Size” section on page 3-15
• “Activating the Upstream Scrambler” section on page 3-16
• “Activating Upstream Differential Encoding” section on page 3-16
• “Activating Upstream Rate Limiting” section on page 3-17