9
Chapter
Chapter 9 Quality of Service (QoS)
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9
Chapter 9
Quality of Service (QoS)
9.1 Overview
This chapter discusses the Device’s
QoS
screens. Use these screens to set up your Device to use QoS
for traffic management.
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. QoS allows the Device to group and
prioritize application traffic and fine-tune network performance.
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.
The Device 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 Internet gaming, and those for which jitter alone is a problem such as Internet radio or
streaming video.
9.1.1 What You Can Do in this Chapter
• Use the
General
screen to enable QoS, set the bandwidth, and allow the Device to automatically
assign priority to upstream traffic according to the IP precedence or packet length (
• Use the
Queue Setup
screen to configure QoS queue assignment (
• Use the
Class Setup
screen to set up classifiers to sort traffic into different flows and assign
priority and define actions to be performed for a classified traffic flow (
• Use the
Policer Setup
screen to add, edit or delete QoS policers (
• Use the
Game List
screen to to give priority to traffic for specific games (
9.1.2 What You Need to Know
The following terms and concepts may help as you read this chapter.