ZyXEL Communications XS-3900-48F, User Manual

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XS3900-48F User’s Guide
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H A P T E R
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Classifier
This chapter introduces and shows you how to configure the packet classifier on the Switch.
18.1 About the Classifier and QoS
Quality of Service (QoS) refers to both a network's ability to deliver data with minimum delay, and
the networking methods used to control the use of bandwidth. Without QoS, all traffic data is
equally likely to be dropped when the network is congested. This can cause a reduction in network
performance and make the network inadequate for time-critical application such as video-on-
demand.
A classifier groups traffic into data flows according to specific criteria such as the source address,
destination address, source port number, destination port number or incoming port number. For
example, you can configure a classifier to select traffic from the same protocol port (such as Telnet)
to form a flow.
Configure QoS on the Switch to group and prioritize application traffic and fine-tune network
performance. Setting up QoS involves two separate steps:
1
Configure classifiers to sort traffic into different flows.
2
Configure policy rules to define actions to be performed for a classified traffic flow (refer to Chapter
19 on page 157 to configure policy rules).
18.2 Configuring the Classifier
Use the Classifier screen to define the classifiers. After you define the classifier, you can specify
actions (or policy) to act upon the traffic that matches the rules. To configure policy rules, refer to
Chapter 19 on page 157 .