ZyXEL Communications NBG420N - Manual (Page 94)

Chapter 7 Wireless LAN
NBG420N User’s Guide
94
7.4.1 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.
WMM QoS prioritizes wireless traffic according to delivery requirements. 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.
The NBG420N uses WMM QoS to prioritize traffic streams according to the IEEE 802.1q tag
or DSCP information in each packet’s header. The NBG420N automatically determines the
priority to use for an individual traffic stream. This prevents reductions in data transmission
for applications that are sensitive to latency (delay) and jitter (variations in delay).
7.4.1.1 WMM QoS Priorities
The following table describes the WMM QoS priority levels that the NBG420N uses.
7.5 General Wireless LAN Screen
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If you are configuring the NBG420N from a computer connected to the
wireless LAN and you change the NBG420N’s SSID, channel or security
settings, you will lose your wireless connection when you press Apply to
confirm. You must then change the wireless settings of your computer to
match the NBG420N’s new settings.
Click Network > Wireless LAN to open the General screen.
Table 28 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.
video
(WMM_VIDEO) Typically used for traffic which has some tolerance for jitter but needs to be
prioritized over other data traffic.
best effort
(WMM_BEST_EFFORT) 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
(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.