ZyXEL Communications P-335WT ユーザーズマニュアル

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P-335 Series User’s Guide
103 
Chapter 5 Wireless LAN (P-335WT)
5.8  WMM QoS
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.
5.8.1  WMM QoS Example
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.
5.8.2  WMM QoS Priorities
The following table describes the priorities that you can apply to traffic that the Prestige sends 
to the wireless network.
Table 40   WMM QoS Priorities
PRIORITY LEVELS:
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.