Configuring
Quality
of
Service
D-Link
Unified
Access
Point
Administrator’s
Guide
November
2011
Page
104
Unified
Access
Point
Administrator’s
Guide
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
for
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
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.
cwMax
(Maximum
Contention
Window)
The
value
specified
for
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
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
Length
The
Max.
Burst
Length
is
an
AP
EDCA
parameter
and
only
applies
to
traffic
flowing
from
the
AP
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.
Wi-Fi Multimedia Settings
Wi
‐
Fi
MultiMedia
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
UAP
control
downstream
traffic
flowing
from
the
AP
to
client
station
(AP
EDCA
parameters)
and
the
upstream
traffic
flowing
from
the
station
to
the
AP
(station
EDCA
parameters).
Disabling
WMM
deactivates
QoS
control
of
station
EDCA
parameters
on
upstream
traffic
flowing
from
the
station
to
the
AP.
With
WMM
disabled,
you
can
still
set
some
parameters
on
the
downstream
traffic
flowing
from
the
AP
to
the
client
station
(AP
EDCA
parameters).
To
disable
WMM
extensions,
click
Disabled
.
To
enable
WMM
extensions,
click
Enabled
.
Table
40:
QoS
Settings
(Cont.)
Field
Description
