ZyXEL Communications G-3000H User Manual

G-3000H User’s Guide

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Chapter 5 Wireless Configuration

WMM (Wi-Fi MultiMedia) QoS (Quality of Service) ensures quality of service in wireless 
networks for multimedia applications. WMM QoS prioritizes wireless traffic according to the 
delivery requirements of the individual and applications. WMM QoS is a part of the IEEE 
802.11e QoS enhancement to certified Wi-Fi wireless networks.

On APs without WMM QoS, all traffic streams are given the same access throughput to the 
wireless network. If the introduction of another traffic stream creates a data transmission 
demand that exceeds the current network capacity, then the new traffic stream reduces the 
throughput of the other traffic streams.

The ZyAIR uses WMM QoS to prioritize traffic streams according to the needs of the 
application. The ZyAIR automatically determines the priority to use for an individual traffic 
stream. This prevents reductions in data transmission for applications that are sensitive to jitter 
(variations in delay).

The following table describes the WMM QoS priority levels that the ZyAIR uses.

Network traffic can be classified by setting the ToS (Type Of Service) values at the data 
source (for example, at the Prestige) so a server can decide the best method of delivery, that is 
the least cost, fastest route and so on. 

Table 10   WMM QoS Priorities

voice

Typically used for traffic that is especially sensitive to jitter. Use this priority to 

reduce latency for improved voice quality.

video

Typically used for traffic which has some tolerance for jitter but needs to be 

prioritized over other data traffic.

besteffort

Typically used for traffic from applications or devices that lack QoS 

capabilities. Use best effort priority for traffic that is less sensitive to latency, 

but is affected by long delays, such as Internet surfing.

background

This is typically used for non-critical traffic such as bulk transfers and print jobs 

that are allowed but that should not affect other applications and users. Use 

background priority for applications that do not have strict latency and 

throughput requirements.