Configuring Advanced Settings
D-Link
Unified Wired and Wireless Access System
Oct. 2015
Page 623
D-Link UWS User Manual
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 1024. The
value for cwmax must be higher than the value for cwmin.
Max. Burst
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 0.0 through 999.
General Parameters
WMM Mode
Wi-Fi MultiMedia
(WMM) is enabled by default. With WMM enabled, QoS
prioritization and coordination of wireless medium access is on. With WMM
enabled, QoS settings on the D-Link Unified Switch control
downstream
traffic
flowing from the access point to client station (AP EDCA parameters) and the
upstream
traffic flowing from the station to the access point (station EDCA
parameters).
Disabling WMM deactivates QoS control of station EDCA parameters on
upstream
traffic flowing from the station to the access point
With WMM disabled, you can still set some parameters on the downstream
traffic flowing from the access point to the client station (AP EDCA parameters).
To disable WMM extensions, click
Disabled
.
To enable WMM extensions, click
Enabled
.
Station EDCA Parameters
Queue
Queues are defined for different types of data transmitted from station-to-AP:
• Data 0 (Voice)—Highest priority queue, minimum delay. Time-sensitive
data such as VoIP and streaming media are automatically sent to this queue.
• Data 1(Video)—Highest 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 for data
frames. The wait time is measured in slots. Valid values for AIFS are 1 through
255.
Table 357: QoS Settings (Cont.)
Field
Description