Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.02.xx and greater

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Wireless Local Area Networks (WLANs)
Traffic Management (QoS)
The Wireless Edge Services xl Module can configure RPs to support SVP—
that is, to recognize SVP frames, place them in priority queues, and transmit
them with a zero backoff time. If your network includes a SpectraLink server
and SVP-capable phones, you should enable this support in the WLAN that
includes these phones.
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 prior-
itization 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.