Dell PowerConnect W-Airwave W-Airwave 7.2 Configuration Guide - Page 118

Profiles > SSID > EDCA Station Wireless Multimedia (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 802.1d priority tags, as shown in Table 49. Table 51 WMM Access Categories and 802.1d Tags WMM Access Category Description 802.1d 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 0, 3 support QoS Background Low priority traffic (file downloads, print jobs) 2, 1 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. WMM is an extension to the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol's Distributed Coordination Function (DCF). The collision resolution algorithm responsible for traffic prioritization depends on the following configurable parameters for each AC:  arbitrary inter-frame space number (AIFSN)  minimum and maximum contention window (CW) size For each AC, the backoff time is the sum of the AIFSN and a random value between 0 and the CW value. The AC with the lowest backoff time is granted the opportunity to transmit (TXOP). Frames with the highest priority AC are more likely to get TXOP as they tend to have the lowest backoff times (a result of having smaller AIFSN and CW parameter values). The value of the CW varies through time as the CW doubles after each collision up to the maximum CW. The CW is reset to the minimum value after successful transmission. In addition, you can configure the TXOP duration for each AC. On the controller, you configure the AC priorities in the WLAN EDCA parameters profile. There are two sets of EDCA profiles you can configure:  AP parameters affect traffic from the AP to the client  STA parameters affect traffic from the client to the AP Perform these steps to create or edit Event Station profiles. 1. Select Profiles > SSID > EDCA Station in the Dell PowerConnect W Navigation pane. This page summarizes the current cluster profiles. 2. Select the Add button to create a new EDCA Station profile, or click the pencil icon to edit an existing profile. The Details page appears. Complete the settings as described in Table 28: Table 52 Profiles > SSID > EDCA Station Profile Settings Field Default Description General Settings Folder Name Top Blank Set the folder with which the profile is associated. The drop-down menu displays all folders available for association with the profile. Name of the EDCA STA profile. 118 | Dell PowerConnect W Configuration Reference Dell PowerConnect W AirWave 7.2 | Configuration Guide