Software User Manual
D-Link Unified Access System
02/15/2011
Document 34CS3000-SWUM104-D10
Page 161
Table 60
describes the QoS settings you can configure.
Table 60: QoS Settings
Field
Description
Queue
Queues are defined for different types of data transmitted from AP-to-station:
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).
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.
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 1023. The value for
“
cwmin
” must be lower than the value for “
cwmax
”.
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.
Once the Maximum Contention Window size is reached, retries will continue until a
maximum number of retries allowed is reached.
Valid values for the “cwmax” are 1, 3, 7, 15, 31, 63, 127, 255, 511, or 1023. The value
for “cwmax” must be higher than the value for “cwmin”.
Max. Burst Length
AP EDCA Parameter Only
(The Max. Burst Length applies only to traffic flowing from
the access point to the client station.)
This value specifies (in milliseconds) the Maximum Burst Length allowed for packet
bursts on the wireless network. A
packet burst
is a collection of multiple frames
transmitted without header information. The decreased overhead results in higher
throughput and better performance.
Valid values for maximum burst length are 0 through 999.
