Distribution of Remaining Bandwidth Using Ratio
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
!
policy-map vlan10_policy
!
policy-map vlan20_policy
!
!
interface GigabitEthernet 1/0/0.10
!
interface GigabitEthernet 1/0/0.20
Verifying Bandwidth Remaining Ratios: Example
The following sample output from the show policy-map interface command indicates that
bandwidth-remaining ratios are configured on class-level queues in the policy maps named
vlan10_policy and child_policy, which are attached to the Gigabit Ethernet subinterface 1/0/0.10.
Router# show policy-map interface GigabitEthernet1/0/0.10
Service-policy output: vlan10_policy
Cisco 10000 Series Router Quality of Service Configuration Guide
5-22
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
class precedence_2
shape average 500000
bandwidth remaining ratio 60 <---- Class-level ratio
class class-default
shape average 1000000
bandwidth remaining ratio 10 <---- Subinterface-level ratio
service-policy child-policy
class class-default
shape average 1000000
bandwidth remaining ratio 100 <---- Subinterface-level ratio
service-policy child_policy
encapsulation dot1q 10
service-policy output vlan10_policy
encapsulation dot1q 20
service-policy output vlan20_policy
Class-map: class-default (match-any)
0 packets, 0 bytes
30 second offered rate 0 bps, drop rate 0 bps
Match: any
0 packets, 0 bytes
Chapter 5
Distributing Bandwidth Between Queues
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