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

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Packets arrive at an egress line module that has no queues allocated for their
traffic class.
Traffic-Class Groups Overview
You can put traffic classes into a group to create a hierarchy of scheduler nodes and
queues. Organizing traffic into multiple traffic-class groups enables you to manage
and shape traffic—by service class, for example—when the traffic classes are
distributed across different VCs. A traffic-class group contains one or more traffic
classes, but a particular traffic class can belong only to a single group—either the
default group or one named group.
You can configure an auto-strict group and up to three extended traffic-class groups.
You must put traffic classes that require strict-priority scheduling in the auto-strict
group. You can optionally put traffic classes that need a separate round robin (for
example, video) in an extended group.
A traffic class that is not contained in any named group is considered to belong to
the default group. Traffic classes are placed in the default traffic-class group when
the classes are configured—you can then move a class to another traffic-class group.
When you delete a traffic-class from a named group, the class is automatically moved
to the default traffic-class group. ATM VC nodes that are configured in the default
group (which is the factory default configuration) receive backpressure from the
segmentation and reassembly (SAR) feature in the default qos-mode-port node.
Traffic-class groups are global in scope by default. However, you might want to
manage certain traffic classes through particular line modules. If you have already
created a traffic-class group, you can subsequently specify a slot number to create
a local instance of the group that is restricted to the module occupying that slot.
Characteristics configured for the local group on the line module override those of
the global group, for only that line module. Traffic classes in a globally scoped
traffic-class group cannot belong to any other group. Traffic classes in a local
traffic-class group cannot belong to any other group.
Related Topics
Configuring Traffic Classes That Define Service Levels on page 14
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Configuring Traffic-Class Groups That Define Service Levels on page 15
Configuring Traffic Classes That Define Service Levels
The router supports up to eight global traffic classes. Each traffic class can appear in
only one traffic-class group. If not explicitly added to a traffic-class group, the traffic
class is considered to be ungrouped.
To configure a traffic class:
1.
Create a traffic class by assigning a name that represents the type of service and
enter Traffic Class Configuration mode.
host1(config)# traffic-class low-loss1
host1(config-traffic-class)#
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Configuring Traffic Classes That Define Service Levels
JUNOSe 11.1.x Quality of Service Configuration Guide