Configuring
Quality
of
Service
D-Link
Unified
Access
Point
Administrator’s
Guide
November
2011
Page
105
Unified
Access
Point
Administrator’s
Guide
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.
cwMin
(Minimum
Contention
Window)
This
parameter
is
used
by
the
algorithm
that
determines
the
initial
random
backoff
wait
time
(window)
for
retry
of
a
data
transmission
during
a
period
of
contention
for
Unified
Access
Point
resources.
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
will
be
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.
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.
TXOP
Limit
The
TXOP
Limit
is
a
station
EDCA
parameter
and
only
applies
to
traffic
flowing
from
the
client
station
to
the
AP.
The
Transmission
Opportunity
(TXOP)
is
an
interval
of
time,
in
milliseconds,
when
a
WME
client
station
has
the
right
to
initiate
transmissions
onto
the
wireless
medium
(WM)
towards
the
Unified
Access
Point.
The
TXOP
Limit
maximum
value
is
65535.
Other QoS Settings
No
Acknowledgement
Select
On
to
specify
that
the
AP
should
not
acknowledge
frames
with
QosNoAck
as
the
service
class
value.
APSD
Select
On
to
enable
Automatic
Power
Save
Delivery
(APSD),
which
is
a
power
management
method.
APSD
is
recommended
if
VoIP
phones
access
the
network
through
the
AP.
Note:
After
you
configure
the
QoS
settings,
you
must
click
Apply
to
apply
the
changes
and
to
save
the
settings.
Changing
some
settings
might
cause
the
AP
to
stop
and
restart
system
processes.
If
this
happens,
wireless
clients
will
temporarily
lose
connectivity.
We
recommend
that
you
change
AP
settings
when
WLAN
traffic
is
low.
Table
40:
QoS
Settings
(Cont.)
Field
Description
