Alcatel-Lucent 7450 - Page 66

QoS Policies
66 Quality of Service Guide
Figure 9 depicts how child queues and schedulers interact with their parent scheduler to
receive bandwidth. The scheduler distributes bandwidth to the children by first using each
child’s CIR according to the CIR-level parameter (CIR L8 through CIR L1 weighted loops).
The weighting at each CIR-Level loop is defined by the CIR weight parameter for each child.
The scheduler then distributes any remaining bandwidth to the children up to each child’s rate
parameter according to the Level parameter (L8 through L1 weighted loops). The weighting
at each level loop is defined by the weight parameter for each child.
Figure 9: Virtual Scheduler Internal Bandwidth Allocation
al_0188
Child
Scheduler
Child Offered Within CIR and Above CIR Load
Limited by Child Maximum Rate (PIR)
Child Served Within CIR Loop According to
Provisioned CIR-Level
Scheduler CIR Based on
Provisioned Value or
Sum of Child CIR Values
Rate Limiting Strict Loop
Receives Bandwidth
According to it’s Offered
Load Within CIR and
Offered Load Above CIR
Rate Limiting Strict Loop
Distributes Available
Bandwidth to Each Child
According to Child
Offered Load Within and
Offered Load Above
Child CIR
Scheduler Rate (PIR)
Based on Provisioned
Value
Child Served By Above CIR Loop According to
Provisioned Level
Prioritizing Loop (Weighted or Strict)
Legend
Maximum and Committed
Rate Parameters
Bandwidth Dependency Association
Bandwidth Allocation
CIR-Weight Determines Ratio of Bandwidth for
Child When Multiple Children Are Mapped to
Same Within CIR Loop
Weight Determines Ratio of Bandwidth for
Child When Multiple Children Are Mapped to
Same Above CIR Loop
Rate
Limiting
StrictLoop
Within
CIR
StrictLoop
CIRL
8
CIRL
7
CIRL
6
CIRL
5
CIRL
4
CIRL
3
CIRL
2
Child
Queue
Child Undefined CIR
Level Forces All
Offered Load For
Child to be Treated as
Above CIR Level
and Weight
Offered Load Within CIR
Offered Load Within CIR
OR
CIRL
1
L8
L7
L6
L5
L4
L3
L2
L1
High
Priority
Low
Priority
Scheduler
Loop Within
Policy
Above
CIR
StrictLoop