<s>
Application	B-Protocol
Request	I-Protocol
Routing	I-Protocol
(	O
ARR	O
)	O
is	O
an	O
extension	O
to	O
Internet	B-Application
Information	I-Application
Server	I-Application
(	O
IIS	O
)	O
,	O
which	O
enables	O
an	O
IIS	B-Application
server	I-Application
to	O
function	O
as	O
a	O
load	B-Application
balancer	I-Application
.	O
</s>
<s>
With	O
ARR	O
,	O
an	O
IIS	B-Application
server	I-Application
can	O
be	O
configured	O
to	O
route	O
incoming	O
requests	O
to	O
one	O
of	O
multiple	O
web	B-Application
servers	I-Application
using	O
one	O
of	O
several	O
routing	O
algorithms	O
.	O
</s>
<s>
By	O
load	B-Application
balancing	I-Application
requests	O
,	O
high	O
availability	O
of	O
web	B-Application
servers	I-Application
can	O
be	O
achieved	O
without	O
incurring	O
the	O
typically	O
high	O
costs	O
of	O
dedicated	O
load	B-Application
balancing	I-Application
products	O
.	O
</s>
<s>
The	O
current	O
version	O
is	O
supported	O
in	O
x86	B-Operating_System
and	O
x64	B-Device
,	O
and	O
can	O
be	O
installed	O
on	O
IIS	O
7.0	O
or	O
later	O
(	O
Windows	O
2008	O
or	O
later	O
)	O
.	O
</s>
<s>
ARR	O
can	O
be	O
configured	O
to	O
redirect	O
traffic	O
based	O
on	O
server	O
variables	O
,	O
URLs	O
,	O
cookies	B-Application
and	O
more	O
,	O
and	O
performs	O
full	O
layer	O
7	O
load	B-Application
balancing	I-Application
.	O
</s>
<s>
ARR	O
's	O
functionality	O
can	O
be	O
described	O
as	O
a	O
load	B-Application
balancing	I-Application
and	O
reverse	B-General_Concept
proxy	I-General_Concept
,	O
although	O
it	O
is	O
not	O
as	O
advanced	O
as	O
some	O
dedicated	O
reverse	B-General_Concept
proxy	I-General_Concept
products	O
such	O
as	O
Microsoft	O
UAG	B-General_Concept
and	O
dedicated	O
load	B-Application
balancing	I-Application
solutions	O
.	O
</s>
