Classifying your data, Class maps, Classifying your data” on – Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) User Manual

Page 980

Quality of Service (QoS) Introduction

Software Reference for x310 Series Switches

38.8

AlliedWare Plus

Operating System - Version 5.4.4C

C613-50046-01 REV A

Classifying your Data

One of the early steps in setting up QoS on a network is planning and applying your
classification rules. Classification is the process of Filtering and Marking. Filtering involves
sorting your data into appropriate traffic types. Marking involves tagging the data so that
downstream ports and routers can apply appropriate service policy rules.

Figure 38-4

illustrates the classifying process, and will be referred to in the examples that follow.

Figure 38-4: QoS Classification Process

At the premarking stage you can assign your data a particular priority level by giving it a
link level user priority, see

“Link Layer QoS” on page 38.3

, or a network level DSCP

“Differentiated Services Architecture” on page 38.4

. You can also assign the data to a

particular output (or egress) queue.

Class Maps

Class Maps are among the pivotal QoS components. They provide the means that
associate the classified traffic with its appropriate QoS actions. They are the linking
elements for the following functions:

■

classification

■

policy-mapping

■

pre-marking

Figure 38-5

shows the relationship between a class-map and its associated functions.

Note that the relationship between a class-map and a policy-map can be one-to-one or
many-to-one. For information on policy-maps see the section,

“Policy Maps” on

page 38.11

Note

If a conflict occurs between the settings in two class-maps, priority will be
applied to the class-map that was created first.
An example of such a conflict is the arrival of a packet that meets the
classification requirements of two class-maps each configured to the same
policy-map and set to apply different priority settings to the packet.

QoS Classification_BC.eps

mls qos enable

Enables qos on the switch

match