<s>
Deficit	B-Algorithm
Round	I-Algorithm
Robin	I-Algorithm
(	O
DRR	O
)	O
,	O
also	O
Deficit	B-Algorithm
Weighted	I-Algorithm
Round	I-Algorithm
Robin	I-Algorithm
(	O
DWRR	B-Algorithm
)	O
,	O
is	O
a	O
scheduling	O
algorithm	O
for	O
the	O
network	B-Application
scheduler	I-Application
.	O
</s>
<s>
DRR	O
is	O
,	O
like	O
weighted	B-Algorithm
fair	I-Algorithm
queuing	I-Algorithm
(	O
WFQ	B-Algorithm
)	O
,	O
a	O
packet-based	O
implementation	O
of	O
the	O
ideal	O
Generalized	B-Algorithm
Processor	I-Algorithm
Sharing	I-Algorithm
(	O
GPS	O
)	O
policy	O
.	O
</s>
<s>
Like	O
WFQ	B-Algorithm
,	O
DRR	O
offers	O
a	O
minimal	O
rate	O
to	O
each	O
flow	O
whatever	O
the	O
size	O
of	O
the	O
packets	O
is	O
.	O
</s>
<s>
In	O
weighted	B-Algorithm
round	I-Algorithm
robin	I-Algorithm
scheduling	O
,	O
the	O
fraction	O
of	O
bandwidth	O
used	O
depend	O
on	O
the	O
packet	O
's	O
sizes	O
.	O
</s>
<s>
Compared	O
with	O
WFQ	B-Algorithm
scheduler	O
that	O
has	O
complexity	O
of	O
O(log(n )	O
)	O
(	O
n	O
is	O
the	O
number	O
of	O
active	O
flows/queues	B-Operating_System
)	O
,	O
the	O
complexity	O
of	O
DRR	O
is	O
O(1 )	O
,	O
if	O
the	O
quantum	O
is	O
larger	O
than	O
the	O
maximum	O
packet	O
size	O
of	O
this	O
flow	O
.	O
</s>
<s>
Nevertheless	O
,	O
this	O
efficiency	O
has	O
a	O
cost	O
:	O
the	O
latency	O
,	O
i.e.	O
,	O
the	O
distance	O
to	O
the	O
ideal	O
GPS	O
,	O
is	O
larger	O
in	O
DRR	O
than	O
in	O
WFQ	B-Algorithm
.	O
</s>
<s>
An	O
implementation	O
of	O
the	O
deficit	B-Algorithm
round	I-Algorithm
robin	I-Algorithm
algorithm	O
was	O
written	O
by	O
Patrick	O
McHardy	O
for	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
and	O
published	O
under	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
.	O
</s>
