Quality Of Service (Qos); Chapter 10 Quality Of Service (Qos); Overview; What You Can Do In This Chapter - ZyXEL Communications VMG3312-T20A User Manual

Quality of Service (QoS)

10.1 Overview

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.
Configure QoS on the VMG to group and prioritize application traffic and fine-tune network
performance. Setting up QoS involves these steps:
Configure classifiers to sort traffic into different flows.
1
Assign priority and define actions to be performed for a classified traffic flow.
2
The VMG assigns each packet a priority and then queues the packet accordingly. Packets assigned a
high priority are processed more quickly than those with low priority if there is congestion, allowing time-
sensitive applications to flow more smoothly. Time-sensitive applications include both those that require
a low level of latency (delay) and a low level of jitter (variations in delay) such as Voice over IP (VoIP) or
Internet gaming, and those for which jitter alone is a problem such as Internet radio or streaming video.
This chapter contains information about configuring QoS and editing classifiers.

10.1.1 What You Can Do in this Chapter

• Use the General screen to enable or disable QoS and set the upstream bandwidth
page 147).
• Use the Queue Setup screen to configure QoS queue assignment
• Use the Classification Setup screen to add, edit or delete QoS classifiers
• Use the Shaper Setup screen to limit outgoing traffic transmission rate on the selected interface
(Section 10.6 on page
• Use the Policer Setup screen to control incoming traffic transmission rate and bursts (
page 155).
155).
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(Section 10.4 on page
(Section 10.5 on page
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(Section 10.3 on
148).
151).
Section 10.6 on