Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.01.03 or greater

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Radio Port Configuration

Configuring WMM

The IEEE 802.11e-2005 ratified specification for wireless QoS enhancements

includes packet prioritization, scheduled access, and call admission control.

Eager to spur interoperability among multi-vendor wireless gear, the Wi-Fi

Alliance created a certification process on a subset of 802.11e called Wi-Fi

Multimedia (WMM). WMM divides traffic into four access categories (ACs):

voice, video, best effort, and background.

RPs place traffic in each AC in a separate priority queue. By default, RPs

prioritize frames according to the 802.1p values in their Ethernet headers. The

higher the AC, the higher the QoS its traffic requires, and parameters for the

corresponding queue are established accordingly.

Table 5-3 shows the WMM queues on the ProCurve 210, 220, and 230 RPs. Each

radio on an RP has four queues for outbound wireless traffic. These queues

and all radio WMM settings apply to traffic from the RP to wireless stations.

Table 5-3. WMM Priority Queues

Each outbound radio queue is defined by different WMM parameters, which

determine how the RP contends for the medium in order to transmit frames

in that queue. These parameters include:

■ the arbitration IFS number (AIFSN)—the time that the medium must be

contention free before the RP can attempt to transmit a frame (first

decrementing a random backoff time)

■ the minimum contention window (CW Min)—the maximum value for the

initial random backoff time

■ the maximum contention window (CW Max)—the maximum value for the

random backoff time for a frame that has collided

■ the transmit opportunity (Transmit Ops)—the continuous time during

which a device that has won control of the radio can retain control

Queue Number AC

1 Background

2 Best effort

3Video

4 Voice