<s>
Network	O
Policy	O
and	O
Access	O
Services	O
(	O
NPAS	O
)	O
is	O
a	O
component	O
of	O
Windows	B-Device
Server	I-Device
2008	I-Device
.	O
</s>
<s>
It	O
replaces	O
the	O
Internet	O
Authentication	O
Service	O
(	O
IAS	O
)	O
from	O
Windows	B-Application
Server	I-Application
2003	I-Application
.	O
</s>
<s>
The	O
NPAS	O
server	O
role	O
includes	O
Network	B-Device
Policy	I-Device
Server	I-Device
(	O
NPS	O
)	O
,	O
Health	O
Registration	O
Authority	O
(	O
HRA	O
)	O
,	O
and	O
Host	O
Credential	O
Authorization	O
Protocol	O
(	O
HCAP	O
)	O
.	O
</s>
<s>
In	O
Windows	B-Application
Server	I-Application
2003	I-Application
,	O
IAS	O
is	O
the	O
Microsoft	O
implementation	O
of	O
a	O
Remote	B-Protocol
Authentication	I-Protocol
Dial-In	I-Protocol
User	I-Protocol
Service	I-Protocol
(	O
RADIUS	B-Protocol
)	O
server	O
.	O
</s>
<s>
In	O
Windows	O
Server	O
operating	O
systems	O
later	O
than	O
Windows	B-Application
Server	I-Application
2003	I-Application
,	O
IAS	O
is	O
renamed	O
to	O
NPS	O
.	O
</s>
<s>
NPS	O
is	O
a	O
role	O
service	O
in	O
Windows	B-Device
Server	I-Device
2008	I-Device
which	O
can	O
function	O
as	O
:	O
</s>
<s>
One	O
can	O
use	O
NPS	O
with	O
the	O
Routing	O
and	O
Remote	O
Access	O
service	O
,	O
which	O
is	O
available	O
in	O
Microsoft	O
Windows	O
2000	O
,	O
Windows	B-Application
Server	I-Application
2003	I-Application
,	O
Standard	O
Edition	O
;	O
Windows	B-Application
Server	I-Application
2003	I-Application
,	O
Enterprise	O
Edition	O
;	O
and	O
Windows	B-Application
Server	I-Application
2003	I-Application
,	O
Datacenter	O
Edition	O
.	O
</s>
<s>
When	O
a	O
server	O
running	O
NPS	O
is	O
a	O
member	O
of	O
an	O
Active	B-Protocol
Directory	I-Protocol
Domain	I-Protocol
Services	I-Protocol
(	O
AD	B-Protocol
DS	I-Protocol
)	O
domain	O
,	O
NPS	O
uses	O
the	O
directory	O
service	O
as	O
its	O
user	O
account	O
database	O
and	O
is	O
part	O
of	O
a	O
single	O
sign-on	O
solution	O
.	O
</s>
<s>
The	O
same	O
set	O
of	O
credentials	O
is	O
used	O
for	O
network	O
access	O
control	O
(	O
authenticating	O
and	O
authorizing	O
access	O
to	O
a	O
network	O
)	O
and	O
to	O
log	O
on	O
to	O
an	O
AD	B-Protocol
DS	I-Protocol
domain	O
.	O
</s>
