ZyXEL Communications 100-NH ユーザーズマニュアル
Chapter 6 Wireless LAN
NWA1000 Series User’s Guide
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6.10.2 WMM QoS
WMM (Wi-Fi MultiMedia) QoS (Quality of Service) ensures quality of service in wireless networks. It
controls WLAN transmission priority on packets to be transmitted over the wireless network.
controls WLAN transmission priority on packets to be transmitted over the wireless network.
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.
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 priority 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.
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 NWA uses WMM QoS to prioritize traffic streams according to the IEEE 802.1q or DSCP
information in each packet’s header. The NWA automatically determines the priority to use for an
individual traffic stream. This prevents reductions in data transmission for applications that are
sensitive to latency and jitter (variations in delay).
information in each packet’s header. The NWA automatically determines the priority to use for an
individual traffic stream. This prevents reductions in data transmission for applications that are
sensitive to latency and jitter (variations in delay).
6.10.2.1 WMM QoS Priorities
The following table describes the WMM QoS priority levels that the NWA uses.
Roaming
If you have two or more NWAs (or other wireless access points) on your wireless
network, you can enable this option so that wireless devices can change locations
without having to log in again. This is useful for devices, such as notebooks, that
move around a lot.
network, you can enable this option so that wireless devices can change locations
without having to log in again. This is useful for devices, such as notebooks, that
move around a lot.
Antenna
An antenna couples Radio Frequency (RF) signals onto air. A transmitter within a
wireless device sends an RF signal to the antenna, which propagates the signal
through the air. The antenna also operates in reverse by capturing RF signals from
the air.
wireless device sends an RF signal to the antenna, which propagates the signal
through the air. The antenna also operates in reverse by capturing RF signals from
the air.
Positioning the antennas properly increases the range and coverage area of a wireless
LAN.
LAN.
TERM
DESCRIPTION
Table 25
WMM QoS Priorities
Priority Level
description
voice
(WMM_VOICE)
Typically used for traffic that is especially sensitive to jitter. Use this priority to
reduce latency for improved voice quality.
reduce latency for improved voice quality.
video
(WMM_VIDEO)
Typically used for traffic which has some tolerance for jitter but needs to be
prioritized over other data traffic.
prioritized over other data traffic.
best effort
(WMM_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.
best effort priority for traffic that is less sensitive to latency, but is affected by long
delays, such as Internet surfing.
background
(WMM_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.
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.