Manual

AT-WA7400 Management Software User’s Guide
169
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).
For more information, see “QoS Queues and Parameters to
Coordinate Traffic Flow” on page 162.
AIFs
(Inter-Frame Space)
The Arbitration Inter-Frame Spacing (AIFs) specifies a wait time (in
milliseconds) for data frames.
Valid values for AIFs are 1 through 255.
For more information, see “EDCF Control of Data Frames and
Arbitration Interframe Spaces” on page 164.
cwMin
(Minimum Contention Window)
This parameter is input to the algorithm that determines the initial
random backoff wait time (window) for retry of a transmission.
The value specified here in the Minimum Contention Window is the
upper limit (in milliseconds) of a range from which the initial random
backoff wait time is determined.
The first random number generated will be 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 will continue until the size of the random
backoff value reaches the number defined in the Maximum Contention
Window.
Valid values for the
cwmin are 1, 3, 7, 15, 31, 63, 127, 255, 511, or
1024. The value for
cwmin must be lower than the value for cwmax.
For more information, see “Random Backoff and Minimum / Maximum
Contention Windows” on page 165.
cwMax
(Maximum Contention Window)
The value specified here in the Maximum Contention Window is 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.