ZyXEL Communications P-662H User Manual

P-662H/HW-D Series User’s Guide

Chapter 7 Wireless LAN

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WMM (Wi-Fi MultiMedia) QoS (Quality of Service) ensures quality of service in wireless 
networks for multimedia applications.

WMM allows you to prioritize wireless traffic according to the delivery requirements of the 
individual and applications.

WMM is a part of the IEEE 802.11e QoS enhancement to certified Wi-Fi wireless networks.

When WMM QoS is not enabled, 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.

When WMM QoS is enabled, the streams are prioritized according to the needs of the 
application. You can assign different priorities to different applications. This prevents 
reductions in data transmission for applications that are sensitive.

The following table describes the priorities that you can apply to traffic that the ZyXEL 
Device sends to the wireless network.

Table 45   WMM QoS Priorities

Highest

Typically used for voice traffic or video that is especially sensitive to jitter 

(variations in delay). Use the highest priority to reduce latency for improved 

voice quality.

High

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

be prioritized over other data traffic.

Mid 

Typically used for traffic from applications or devices that lack QoS 

capabilities. Use mid priority for traffic that is less sensitive to latency, but is 

affected by long delays, such as Internet surfing.

Low

This is typically used for non-critical “background” traffic such as bulk transfers 

and print jobs that are allowed but that should not affect other applications and 

users. Use low priority for applications that do not have strict latency and 

throughput requirements.