Configure Services
QoS

Time critical data traffic such as voice and video benefit from QoS, which can be configured to give voice and video higher priority. This allows for smooth voice communication, jitter free video, and reliable delivery of E-Mail configured with a lower priority.

QoS is disabled by default. The most important guideline in QoS deployment is to be familiar with the traffic on the wireless LAN. It is important to know the applications used by wireless client devices, the delay sensitivity of the applications, and the amount of traffic associated with the applications. QoS does not create additional bandwidth for the wireless LAN. Rather it helps control the allocation of bandwidth. If there is adequate bandwidth on the WLAN, QoS may not be needed.

QoS on the wireless LAN focuses on downstream prioritization from the AP. Figure shows the upstream and downstream traffic flow. The radio downstream flow is traffic transmitted out the AP radio to a wireless client device. This traffic is the main focus for QoS on a wireless LAN. The radio upstream flow is traffic transmitted out the wireless client device to the AP. QoS for wireless LANs does not affect this traffic.

The Ethernet downstream flow is traffic sent from a switch or a router to the Ethernet port on the AP. If QoS is enabled on the switch or router, the switch or router might prioritize and rate-limit traffic to the AP. The Ethernet upstream flow is traffic sent from the AP Ethernet port to a switch or router on the wired LAN. The AP does not prioritize traffic that it sends to the wired LAN based on traffic classification.

When QoS is enabled, the AP queues packets based on the Layer 2 class of service value for each packet. The AP applies QoS policies in the order shown in Figure . From the Services > QoS Policies Page, configuring QoS is a two step process .

  1. Create/Edit the policy
  2. Apply the policy

The steps to configure QoS can be found in the Topics section of the online AP Help or through the link below. The Traffic Class Definition page is shown in Figure along with the common values in Figure .

The Advanced QoS page is shown in Figure . If QoS Element for Wireless Phones feature is enabled, traffic from wireless phone clients have a higher priority than the rest of the clients. When Internet Group Membership Protocol (IGMP) snooping is enabled on a switch and a client roams from one AP to another, the client's multicast session is dropped. When the IGMP snooping helper of the AP is enabled, the AP sends a general IGMP query to the network infrastructure on behalf of the client every time the client associates or reassociates to the AP. By doing so, the multicast stream is maintained for the client as it roams. The Snooping Helper is enabled by default. To disable, click the Disable selection and click Apply.


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