Cisco WAP131 Administration Manual page 110

Wireless
Quality of Service
STEP 4
Cisco WAP131 and WAP351 Administration Guide
• Optimized for Voice—Populates the WAP device and the Station EDCA
parameters with values that are best for voice traffic.
• Custom—Enables you to choose custom EDCA parameters.
These four queues are defined for different types of data transmitted from WAP-
to-station. If you choose a Custom template, the parameters that define the queues
are configurable; otherwise, they are set to predefined values appropriate to your
selection. The four queues are:
• Data 0 (Voice)—High priority queue, minimum delay. Time-sensitive data
such as VoIP and streaming media are automatically sent to this queue.
• Data 1 (Video)—High priority queue, minimum delay. Time-sensitive video
data is automatically sent to this queue.
• Data 2 (Best Effort)—Medium priority queue, medium throughput and
delay. Most traditional IP data is sent to this queue.
• Data 3 (Background)—Lowest priority queue, high throughput. Bulk data
that requires maximum throughput and is not time-sensitive is sent to this
queue (FTP data, for example).
Configure the following EDCA and Station EDCA parameters:
These parameters are configurable only if you choose Custom in the
NOTE
previous step.
• Arbitration Inter-Frame Space—A wait time for data frames. The wait time
is measured in slots. Valid values for AIFS are 1 through 255.
• Minimum Contention Window—An input to the algorithm that determines
the initial random backoff wait time (window) for retry of a transmission.
This value is the upper limit (in milliseconds) of a range from which the initial
random backoff wait time is determined. The first random number generated
is a number between 0 and the number specified here. If the first random
backoff wait time expires before the data frame is sent, a retry counter is
incremented and the random backoff value (window) is doubled. Doubling
continues until the size of the random backoff value reaches the number
defined in the Maximum Contention Window.
Valid values are 1, 3, 7, 15, 31, 63, 127, 255, 511, or 1024. This value must be
lower than the value for the Maximum Contention Window.
• Maximum Contention Window—The upper limit in milliseconds for the
doubling of the random backoff value. This doubling continues until either the
data frame is sent or the Maximum Contention Window size is reached.
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