Cisco 10000 Series User Manual

13-26
Cisco 10000 Series Router Quality of Service Configuration Guide
OL-7433-09
Chapter 13 Defining QoS for Multiple Policy Levels
Configuration Examples
Configuring Bandwidth-Remaining Ratios on ATM Subinterfaces: Example
The following example shows how to differentiate one ATM PVC from another during congestion by
using bandwidth-remaining ratios. In the example, during periods of congestion in which the traffic on
all PVCs on the interface exceeds the interface speed, the router uses the configured
bandwidth-remaining ratio of 10 to determine the amount of excess (unused by priority traffic)
bandwidth to allocate to non-priority traffic on PVC 0/200, relative to the other ATM PVCs configured
on the interface.
policy-map Child
class precedence_0
bandwidth 100
class precedence_1
bandwidth 10000
!
policy-map Parent
class class-default
bandwidth remaining ratio 10
service-policy Child
!
interface ATM2/0/3.200 point-to-point
ip address 10.20.1.1 255.255.255.0
pvc 0/200
protocol ip 10.20.1.2
vbr-nrt 50000
encapsulation aal5snap
service-policy output Parent
Note If PVC 98/204 is configured on the same interface as PVC 0/200 and with a bandwidth-remaining ratio
of 1, during times of congestion PVC 0/200 would have 10 times more bandwidth available to it for
non-priority traffic than PVC 98/204 would have.
For information on bandwidth-remaining ratios, see “Distribution of Remaining Bandwidth Using
Ratio” section on page 5-14 or the Distribution of Remaining Bandwidth Using Ratio,
Release 12.2(31)SB2 feature module.
Configuring Bandwidth-Remaining Ratios on Class Queues: Example
In the following sample configuration, the vlan10_policy is applied on the subinterface Gigabit
Ethernet
1/0/0.10 and the vlan20_policy is applied on the subinterface Gigabit Ethernet 1/0/0.20. During
congestion on the interface, subinterface GE 1/0/0.20 has 10 times more available bandwidth than
subinterface GE1/0/0.10 because the bandwidth-remaining ratio for subinterface GE 1/0/0.20 is 10 times
more than the bandwidth-remaining ratio for subinterface 1/0/0.10: 100 on subinterface 1/0/0.20 and 10
on subinterface 1/0/0.10.
When congestion occurs within a subinterface level, the class queues receive bandwidth according to the
class-level bandwidth-remaining ratios. In the example, the bandwidth for classes precedence_0,
precedence_1, and precedence_2 is allocated based on the bandwidth-remaining ratios of the classes: 20,
40, and 60, respectively.
policy-map child-policy
class precedence_0
shape average 500000
bandwidth remaining ratio 20 <---- Class-level ratio
class precedence_1
shape average 500000
bandwidth remaining ratio 40 <---- Class-level ratio

Cisco 10000 Series Specifications

General

Brand	Cisco
Model	10000 Series
Category	Network Router
Language	English