ZyXEL Communications 802.11g ADSL 2+ 4-Port Security Gateway HW-D Series - Manual (Page 141)

P-662H/HW-D Series User’s Guide
Chapter 7 Wireless LAN 141
7.8 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.
7.8.1 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.
7.8.2 WMM QoS Priorities
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
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.