<s>
In	O
routers	B-Protocol
and	O
switches	B-Protocol
,	O
active	B-Algorithm
queue	I-Algorithm
management	I-Algorithm
(	O
AQM	O
)	O
is	O
the	O
policy	O
of	O
dropping	O
packets	O
inside	O
a	O
buffer	O
associated	O
with	O
a	O
network	B-Protocol
interface	I-Protocol
controller	I-Protocol
(	O
NIC	O
)	O
before	O
that	O
buffer	O
becomes	O
full	O
,	O
often	O
with	O
the	O
goal	O
of	O
reducing	O
network	O
congestion	O
or	O
improving	O
end-to-end	O
latency	O
.	O
</s>
<s>
This	O
task	O
is	O
performed	O
by	O
the	O
network	B-Application
scheduler	I-Application
,	O
which	O
for	O
this	O
purpose	O
uses	O
various	O
algorithms	O
such	O
as	O
random	B-Algorithm
early	I-Algorithm
detection	I-Algorithm
(	O
RED	B-Algorithm
)	O
,	O
Explicit	O
Congestion	O
Notification	O
(	O
ECN	O
)	O
,	O
or	O
controlled	B-Algorithm
delay	I-Algorithm
(	O
CoDel	B-Algorithm
)	O
.	O
</s>
<s>
RFC	O
7567	O
recommends	O
active	B-Algorithm
queue	I-Algorithm
management	I-Algorithm
as	O
a	O
best	O
practice	O
.	O
</s>
<s>
An	O
Internet	B-Protocol
router	I-Protocol
typically	O
maintains	O
a	O
set	O
of	O
queues	O
,	O
one	O
or	O
more	O
per	O
interface	O
,	O
that	O
hold	O
packets	O
scheduled	O
to	O
go	O
out	O
on	O
that	O
interface	O
.	O
</s>
<s>
Drop-tail	O
queues	O
have	O
a	O
tendency	O
to	O
penalise	O
bursty	O
flows	O
,	O
and	O
to	O
cause	O
global	B-Protocol
synchronisation	I-Protocol
between	O
flows	O
.	O
</s>
<s>
By	O
providing	O
endpoints	O
with	O
congestion	O
indication	O
before	O
the	O
queue	O
is	O
full	O
,	O
AQM	O
disciplines	O
are	O
able	O
to	O
maintain	O
a	O
shorter	O
queue	O
length	O
than	O
drop-tail	O
queues	O
,	O
which	O
combats	O
bufferbloat	O
and	O
reduces	O
network	B-Protocol
latency	I-Protocol
.	O
</s>
<s>
Early	O
AQM	O
disciplines	O
(	O
notably	O
RED	B-Algorithm
and	O
SRED	O
)	O
require	O
careful	O
tuning	O
of	O
their	O
parameters	O
in	O
order	O
to	O
provide	O
good	O
performance	O
.	O
</s>
<s>
Modern	O
AQM	O
disciplines	O
(	O
ARED	O
,	O
Blue	B-Protocol
,	O
PI	O
,	O
CoDel	B-Algorithm
,	O
CAKE	O
)	O
are	O
self-tuning	O
,	O
and	O
can	O
be	O
run	O
with	O
their	O
default	O
parameters	O
in	O
most	O
circumstances	O
.	O
</s>
<s>
An	O
active	B-Algorithm
queue	I-Algorithm
management	I-Algorithm
and	O
denial-of-Service	O
(	O
AQM&DoS	O
)	O
simulation	O
platform	O
is	O
established	O
based	O
on	O
the	O
NS-2	B-Language
simulation	O
code	O
of	O
the	O
RRED	O
algorithm	O
.	O
</s>
<s>
and	O
AQM	O
algorithms	O
(	O
RED	B-Algorithm
,	O
RRED	O
,	O
SFB	O
,	O
etc	O
.	O
)	O
.	O
</s>
