U-Apsd; Traffic Stream Metrics; Using The Gui To Configure Voice Parameters - Cisco SD2008T-NA Configuration Manual

Chapter 4 Configuring Controller SettingsWireless Device Access
You must enable admission control (ACM) for CCXv4 clients that have WMM enabled. Otherwise, CAC
Note
does not operate properly.

U-APSD

Unscheduled automatic power save delivery (U-APSD) is a QoS facility defined in IEEE 802.11e that
extends the battery life of mobile clients. In addition to extending battery life, this feature reduces the
latency of traffic flow delivered over the wireless media. Because U-APSD does not require the client to
poll each individual packet buffered at the access point, it allows delivery of multiple downlink packets
by sending a single uplink trigger packet. U-APSD is enabled automatically when WMM is enabled.

Traffic Stream Metrics

In a voice-over-wireless LAN (VoWLAN) deployment, four variables can affect audio quality: packet
latency, packet jitter, packet loss, and roaming time. These variables are referred to as traffic stream
metrics (TSM). An administrator can isolate poor voice quality issues by studying these variables.
The metrics consist of a collection of uplink (client side) and downlink (access point side) statistics
between an access point and a client device that supports CCX v4. If the client is not CCX v4 compliant,
only downlink statistics are captured. The client and access point measure these metrics. The access
point also collects the measurements every 5 seconds, prepares 90-second reports, and then sends the
reports to the controller. The controller organizes the uplink measurements on a client basis and the
downlink measurements on an access point basis and maintains an hour's worth of historical data. To
store this data, the controller requires 32 MB of additional memory for uplink metrics and 4.8 MB for
downlink metrics.
TSM can be configured through either the GUI or the CLI on a per radio-band basis (for example, all
802.11a radios). The controller saves the configuration in flash memory so that it persists across reboots.
After an access point receives the configuration from the controller, it enables TSM on the specified
radio band.
Access points support TSM in both local and hybrid-REAP modes.
Note

Using the GUI to Configure Voice Parameters

Follow these steps to configure voice parameters using the GUI.
Make sure that the WLAN is configured for WMM and the Platinum QoS level.
Step 1
To disable the radio network, click Wireless and then Network under 802.11a or 802.11b/g, uncheck
Step 2
the 802.11a (or 802.11b/g) Network Status check box, and click Apply.
Click Voice under 802.11a or 802.11b/g. The 802.11a (or 802.11b) > Voice Parameters page appears (see
Step 3
Figure
Ol-9141-03
4-8).
Configuring Voice and Video Parameters
Cisco Wireless LAN Controller Configuration Guide
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