Cisco cBR 8 Configuration Guide

Configuration Examples for Fairness Across DOCSIS Interfaces
This section lists the following sample configurations for the Fairness Across DOCSIS Interfaces feature on
a Cisco CMTS router:
Example: Fairness Across DOCSIS Interfaces
The following sample configuration shows Fairness Across DOCSIS Interfaces feature enabled on the router:
Current configuration : 39682 bytes
!
! Last configuration change at 04:30:02 UTC Wed Jan 19 2
! NVRAM config last updated at 04:23:17 UTC Wed Jan 19 2
!
version 12.2
!
cable clock dti
cable acfe enable
!
.
.
.
Example: Maximum EIR Demand Ratio
The following sample configuration shows maximum EIR demand ratio configured on the router:
Building configuration...
Current configuration : 54253 bytes
!
version 12.2
!
cable clock dti
cable acfe enable
cable acfe max-eir-ratio 20
!
The effect of the cable acfe max-eir-ratio command is demonstrated using a simple BG cluster.
!
interface integrated-Cable1/0/0:0
cable bundle 1
cable rf-bandwidth-percent 10
!
interface Wideband-Cable9/0/0:0
cable bundle 1
cable rf-channels channel-list 0
bandwidth-percent 1
end
!
On this RF channel, 20 percent of the bandwidth is reserved by the ‘bandwidth-percent’ allowing Fairness
Across DOCSIS Interfaces feature to use 27 Mbps, that is: (100 - 20) * 90 * 37.5). If the ‘max-eir-ratio’ is
above 100 and the WB interface has 99 active BE flows and the IC interface has only 1 BE flow, then IC
interface gets only 270 kbps, that is 1/(1+99)*27 of the bonus bandwidth. The BE traffic enjoys perfect fairness
here. However, it is not possible to admit a unicast CIR flow beyond 270 kbps on the IC interface, as it would
exceed the bonus bandwidth. If the ‘max-eir-ratio’ is set to 10, then the IC interface is treated to have 99/10
flows on it, resulting in a higher bonus bandwidth allocation. The ‘max-eir-ratio’ is a trade-off between perfect
fairness and CIR utilization.
Cisco cBR Series Converged Broadband Routers Quality of Services Configuration Guide for Cisco IOS XE Fuji
16.7.x
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Fairness Across DOCSIS Interfaces
Configuration Examples for Fairness Across DOCSIS Interfaces

Cisco cBR 8 Specifications

General

Brand	Cisco
Model	cBR 8
Category	Network Router
Language	English