How to configure Wi-Fi Multimedia

Use the command: traffic-classto set the EDCA back off criteria for the required WMM access category:

traffic-class [backgroundbest-effortvideovoice]

cw-min <0-10> cw-max <0-10> fixed-slot <2-20>

no traffic-class [backgroundbest-effortvideovoice]

On collisions, WMM sets the back off time within the CWmin range and uses a persistence factor (PF) as the coefficient that multiplies the contention window size in successive retransmission attempts following a collision.


	WMM setup may only be entered on a wireless node with an access point role.
Note:	It will distribute the QoS policies to “slave” nodes, for example, non -root bridge,
	workgroup-bridge, etc.

Parameter descriptions

cw-min(Contention Window minimum)

That is the random wait time before retrying the transmission; the initial size of the contention window is within 0~CW min back off slots.

The value specifies the number of back off slots as a power of 2n -1; in example,

cw-min 3 means 23-1=7 back off slots.

cw-min 0 means 20-1=0 back off slots.

cw-max(Contention Window maximum)

That is the maximum size of the contention window.

The value specifies the number of back off slots as a power of 2n -1.

fixed-slot(Arbitrary Inter-Frame Space)

That is the predefined idle time that the station waits before starting the contention window (CW) .

The value specifies the number of back off slots.

Refer to “AT-WR4600 – Command Reference Guide”, for default settings and

Note: recommended configuration for the different W LAN topologies (access point, bridging, etc.).

Page 7 How To: Configure the WLAN with QoS

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