WESM zl Management and Configuration Guide WT.01.28 and greater

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Wireless Local Area Networks (WLANs)
Traffic Management (QoS)
To enable SVP support, complete these steps:
1. Access the Edit screen for the WLAN that includes voice devices:
a. Select Network Setup > WLAN Setup and click the Configuration tab.
b. Select the WLAN and click the Edit button. The Edit screen is displayed.
2. Under Advanced, check the Enable SVP box.
3. Click the OK button.
Note Remember that you are enabling SVP support on the WLAN, not on a particular RP.
Because an RP may carry traffic for several WLANs, it might support SVP for some
stations and not for others.
In other words, all ProCurve RPs can support SVP, but they actually do so only on
the WLANs for which you have enabled such support.
WMM
A wireless network uses a shared medium (a radio). To avoid collisions, 802.11
specifies that all stations and RPs use distributed coordination function (DCF), which
is similar to Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA).
When a wireless device wants to transmit, it selects a random backoff time and then
listens for contention. After the medium has been free for an entire IFS interval (3 ms
in DCF), the device counts down its backoff timer and transmits. Because all devices
compete for the medium on the same footing, the QoS for time-sensitive applications
can be seriously degraded.
WMM is a Wi-Fi protocol that prioritizes wireless traffic, ensuring that the most
important and the most time-sensitive traffic receives a high QoS. WMM is similar
to Enhanced Distributed Channel Access (EDCA), which is the prioritization method
specified in the IEEE 802.11e standard.
Support for WMM is particularly important when mobile users use VoWLAN
applications. It will become increasingly crucial as users demand for a wide array of
applications the same quality of network access that they receive over Ethernet
connections.
Prioritization with WMM
WMM improves QoS by dividing traffic into priority queues, one for each of four
access categories (ACs). The higher the AC, the higher the QoS the traffic requires.