ZyXEL Communications ZyAIR G-3000H, User Manual

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G-3000H User’s Guide
Chapter 5 Wireless Configuration 55
• WPA
• Security Parameters Summary
5.3 WMM QoS
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).
5.3.1 WMM QoS Priorities
The following table describes the WMM QoS priority levels that the ZyAIR uses.
5.3.2 Type Of Service (ToS)
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
PRIORITY LEVEL DESCRIPTION
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.