Juniper JUNOSE 11.1.X - QUALITY OF SERVICE CONFIGURATION GUIDE 3-21-2010, Руководство по настройке

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Chapter 6
QoS Scheduler Hierarchy Overview
This chapter provides information for configuring the QoS scheduler hierarchy using
scheduler profiles on the E Series router.
QoS topics are discussed in the following sections:
■
Scheduler Hierarchy Overview on page 45
■
Configuring a Scheduler Hierarchy on page 47
■
Configuring a Scheduler Profile for a Scheduler Node or Queue on page 48
■
Using Expressions for Bandwidth and Burst Values in a Scheduler
Profile on page 48
Scheduler Hierarchy Overview
The egress line module scheduler is an HRR scheduler. Figure 8 on page 46 is an
example of a QoS scheduler’s hierarchy.
As shown in Figure 8 on page 46, the queues feeding a physical port are organized
in a hierarchy. At each level in the hierarchy, the scheduler uses shaping rates,
hierarchical or assured rates, and relative weights to determine the allocated
bandwidth:
■
The scheduler selects a first-level node based on the allocated bandwidth.
■
The scheduler then selects a second-level node from the group of nodes that are
stacked above the selected first-level node. This selection is also based on the
allocated bandwidth.
■
Finally, the scheduler selects a queue from the group of queues stacked above
the second-level node.
Scheduler Hierarchy Overview
■ 45