Specifications

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Cisco Cable Modem Termination System Feature Guide
0L-1467-02
Chapter 3 Spectrum Management for the Cisco Cable Modem Termination System
Configuration Tasks
Setting Downstream Rate Limiting
Downstream rate limiting enables you to use the token-bucket policing algorithm with traffic shaping
options or the weighted-discard policing algorithm to buffer, shape, or discard packets that exceed a set
bandwidth. Downstream rate limiting is disabled by default.
To enable downstream rate limiting for a downstream port on a Cisco cable interface line card, use one
of the following commands in cable interface configuration mode.
To disable downstream traffic shaping for a downstream port, enter the following command in cable
interface configuration mode:
CMTS01(config-if)# no cable downstream rate-limit
For examples of downstream rate limiting, see the “Downstream Traffic Shaping and Rate Limiting
Examples” section on page 3-59.
Note For more information on the cable downstream rate-limit command, see the Cisco Broadband Cable
Command Reference Guide on Cisco.com and on the Documentation CD-ROM.
Command Purpose
Step 1
CMTS01(config-if)# cable downstream
rate-limit
Enables rate limiting on the downstream port using the
token-bucket policing algorithm. This is the default when no
option is entered.
Step 2
CMTS01(config-if)# cable downstream
rate-limit token-bucket
CMTS01(config-if)# cable downstream
rate-limit token-bucket shaping
CMTS01(config-if)# cable downstream
rate-limit token-bucket shaping granularity
msec
CMTS01(config-if)# cable downstream
rate-limit token-bucket shaping max-delay
msec
Enables rate limiting on the downstream port using the
token-bucket policing algorithm. With this command, the
CMTS automatically drops packets that are in violation of the
allowable bandwidth.
Enables rate limiting on the downstream port using the
token-bucket policing algorithm with traffic shaping.
Enables rate limiting on the downstream port using the
token-bucket policing algorithm with specific traffic-shaping
time granularity. Acceptable values are 1, 2, 4, 8, or 16
milliseconds.
Enables rate limiting on the downstream port using the
token-bucket policing algorithm with specific maximum
traffic-shaping buffering delay. Acceptable values are 128, 256,
512, or 1028 milliseconds.
Step 3
CMTS01(config-if)# cable downstream
rate-limit weighted-discard exp-weight
Enables rate limiting on the downstream port using the
weighted-packet discard policing algorithm and assign a weight
for exponential moving average of loss rate. Acceptable values
are 1 to 4.
Step 4
CMTS01(config-if)# ^Z
CMTS01#
Exits back to EXEC mode so that you can verify the steps.