Qos; Chapter 12 Qos; Overview; What You Need To Know - ZyXEL Communications GS1200 Series User Manual

12.1 Overview

This chapter introduces the configuration and functions of the QoS (Quality of Service) screen.
Occasionally, data might be delayed, depending on the volume of traffic and the capacity of the
equipment. Numeric and text data are usually not affected by delays, because they are reassembled
at the destination. However, when VoIP and streaming videos are reassembled, they might have some
troublesome gaps. 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 applications such as VOD (Video on Demand).
You can enable QoS to have the Switch assign 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.
Figure 42 QoS

12.2 What You Need to Know

The Switch can put packets into the queues according to the port on which the packet is received or
the priority tag in the packet.

Chapter 12 QoS

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QoS