Users Guide

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692 | Voice and Video Dell PowerConnect W-Series ArubaOS 6.1 | User Guide
5. Scroll down to the Wireless Multimedia (WMM) option. Select (check) this option.
6. Modify the DSCP mapping settings, as needed:
DSCP mapping for WMM voice AC—DSCP used to map voice traffic
DSCP mapping for WMM video AC—DSCP used to map video traffic
DSCP mapping for WMM best-effort AC—DSCP used to map best-effort traffic
DSCP mapping for WMM background AC—DSCP used to map background traffic
7. Click Apply.
Using the CLI to map between WMM AC and DSCP
wlan ssid-profile <profile>
wmm-be-dscp <best-effort>
wmm-bk-dscp <background>
wmm-vi-dscp <video>
wmm-vo-dscp <voice>
wmm
Dynamic WMM Queue Management
Traditional wireless networks provide all clients with equal bandwidth access. However, delays or reductions in
throughput can adversely affect voice and video applications, resulting in disrupted VoIP conversations or
dropped frames in a streamed video. Thus, data streams that require strict latency and throughput need to be
assigned higher traffic priority than other traffic types.
The Wi-Fi Alliance defined the Wi-Fi Multimedia (WMM) standard in response to industry requirements for
Quality of Service (QoS) support for multimedia applications for wireless networks. This is defined as per the
IEEE 802.11e standards.
WMM requires:
The access point is Wi-Fi Certified and has WMM enabled
The client device is Wi-Fi Certified
The application supports WMM
Enhanced Distributed Channel Access
WMM provides media access prioritization through Enhanced Distributed Channel Access (EDCA). EDCA
defines four access categories (ACs) to prioritize traffic: voice, video, best effort, and background. These ACs
correspond to 802.1p priority tags, as shown in Table 156 on page 692.
While the WMM ACs designate specific types of traffic, you can determine the priority of the ACs. For example,
you can choose to give video traffic the highest priority. With WMM, applications assign data packets to an AC.
In the client, the data packets are then added to one of the transmit queues for voice, video, best effort, or
background.
Table 156 WMM Access Categories and 802.1p Tags
WMM Access Category Description 802.1p Tag
Voice Highest priority 7, 6
Video Prioritize video traffic above other data traffic 5, 4
Best Effort Traffic from legacy devices or traffic from applications or devices that do
not support QoS
0, 3
Background Low priority traffic (file downloads, print jobs) 2, 1