user manual

Configuring Headend Broadband Access Router Features
Configuring the Upstream Cable Interface
MC-550
Cisco IOS Multiservice Applications Configuration Guide
Verifying Upstream FEC
To verify if FEC is activated or deactivated, enter the more system:running-config command and look
for the cable interface configuration information. If FEC is enabled, an FEC entry will be displayed in
the show running-config output. If FEC is disabled, no FEC entry will be displayed in the output. The
following is an excerpt from the more system:running-config command output.
router# more system:running-config
Building configuration...
!
interface Cable6/0
ip address 1.1.1.1 255.255.255.0
no keepalive
cable insertion-interval 150000
cable downstream annex B
cable downstream modulation 64qam
cable downstream interleave-depth 32
cable downstream symbol-rate 5056941
cable upstream 0 frequency 15008000
cable upstream 0 fec
cable upstream 0 scrambler
no cable upstream 0 shutdown
Troubleshooting Tips
To troubleshoot the configuration, perform the following tasks:
• Make sure the cable connections are not loose or disconnected.
• Make sure the Cisco cable modem card is firmly seated in its chassis slot and the captive installation
screws are tight.
• Make sure you entered the correct slot and port numbers when you typed the command.
• Make sure you entered the correct upstream port number:
– On the MC16C cable modem card, this can be u0 to u5.
– On the MC14C cable modem card, this can be u0 to u3.
– On the MC12C cable modem card, this can be u0 or u1.
– On the MC11C cable modem card, this can be u0 only.
Specifying Upstream Minislot Size
To specify the minislot size (in ticks) for specific upstream cable interfaces, use the following command
in cable interface configuration mode:
Command Purpose
CMTS01(config-if)# cable upstream usport minislot-size
size
Specifies the minislot size in ticks for the selected
upstream interface. Acceptable values are 2, 4, 8, 16, 32,
64, and 128.
Default = 8.