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Command Reference Guide
qos-mode wmm
Use the qos-mode wmm command to enable WiFi multimedia (WMM) quality of service (QoS) mode.
Use the no form of this command to disable WMM mode. Variations of this command include the
following:
qos-mode wmm
qos-mode wmm no-ack
Syntax Description
no-ack
Default Values
By default, WMM QoS mode is disabled.
Command History
Release 15.1
Functional Notes
AOS supports WMM, which adds QoS functionality to the wireless network. QoS helps control the
allocation of bandwidth on the wireless local area network (WLAN). The benefits of QoS may not be
noticed if the traffic load on the wireless network is light. However, QoS benefits will become more
apparent as the traffic load on the WLAN increases.
WMM in AOS is based on the enhanced distributed channel access (EDCA) method. This method ensures
that higher priority traffic has a better chance of being transmitted on the WLAN than lower priority traffic.
There are four priority classes defined in WMM to manage traffic from different applications: voice, video,
best-effort, and background. According to algorithms defined in EDCA, a client with traffic in a higher
priority class, such as voice, will typically back off of the radio frequency (RF) medium for a shorter period
of time than a client with traffic in a lower priority class, such as email. In addition, each priority class is
assigned a transmit opportunity (TXOP), which is a set amount of time during which a client can send as
many frames as possible. Higher priority classes are given a longer TXOP interval than lower priority
classes.
WMM must be enabled on both the access points (APs) and the clients running applications that require
QoS. These applications must be able to support WMM for the QoS functionality to be used. In addition,
the applications must be capable of assigning the appropriate priority class to their generated streams of
traffic.
When acknowledgements are enabled, transmission is more reliable because an acknowledge frame is
returned for every frame received. However, acknowledgement frames increase the amount of traffic on
the WLAN, which results in decreased performance. Disabling acknowledgements means that
transmission will not be as reliable, but performance will be better. For example, having no
acknowledgements would be useful for voice traffic because the speed of transmission is most important
and packet loss to a certain degree is tolerable.
60000CRG0-35E
Optional. Specifies the no acknowledgements be sent.
Command was introduced.
Copyright © 2012 ADTRAN, Inc.
Radio Interface Command Set
2825
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