<s>
Network	B-Architecture
architecture	I-Architecture
is	O
the	O
design	O
of	O
a	O
computer	B-Architecture
network	I-Architecture
.	O
</s>
<s>
In	O
telecommunication	O
,	O
the	O
specification	O
of	O
a	O
network	B-Architecture
architecture	I-Architecture
may	O
also	O
include	O
a	O
detailed	O
description	O
of	O
products	O
and	O
services	O
delivered	O
via	O
a	O
communications	O
network	O
,	O
as	O
well	O
as	O
detailed	O
rate	O
and	O
billing	O
structures	O
under	O
which	O
services	O
are	O
compensated	O
.	O
</s>
<s>
The	O
network	B-Architecture
architecture	I-Architecture
of	O
the	O
Internet	O
is	O
predominantly	O
expressed	O
by	O
its	O
use	O
of	O
the	O
Internet	B-Protocol
protocol	I-Protocol
suite	I-Protocol
,	O
rather	O
than	O
a	O
specific	O
model	O
for	O
interconnecting	O
networks	O
or	O
nodes	O
in	O
the	O
network	O
,	O
or	O
the	O
usage	O
of	O
specific	O
types	O
of	O
hardware	O
links	O
.	O
</s>
<s>
The	O
Open	O
Systems	O
Interconnection	O
model	O
(	O
OSI	O
model	O
)	O
defines	O
and	O
codifies	O
the	O
concept	O
of	O
layered	O
network	B-Architecture
architecture	I-Architecture
.	O
</s>
<s>
Abstraction	B-Architecture
layers	I-Architecture
are	O
used	O
to	O
subdivide	O
a	O
communications	O
system	O
further	O
into	O
smaller	O
manageable	O
parts	O
.	O
</s>
<s>
In	O
distributed	B-Architecture
computing	I-Architecture
,	O
the	O
network	B-Architecture
architecture	I-Architecture
often	O
describes	O
the	O
structure	O
and	O
classification	O
of	O
a	O
distributed	B-Architecture
application	I-Architecture
architecture	O
,	O
as	O
the	O
participating	O
nodes	O
in	O
a	O
distributed	B-Architecture
application	I-Architecture
are	O
often	O
referred	O
to	O
as	O
a	O
network	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
applications	B-Architecture
architecture	I-Architecture
of	O
the	O
public	O
switched	O
telephone	O
network	O
(	O
PSTN	O
)	O
has	O
been	O
termed	O
the	O
Intelligent	O
Network	O
.	O
</s>
<s>
A	O
popular	O
example	O
of	O
such	O
usage	O
of	O
the	O
term	O
in	O
distributed	B-Architecture
applications	I-Architecture
,	O
as	O
well	O
as	O
permanent	O
virtual	O
circuits	O
,	O
is	O
the	O
organization	O
of	O
nodes	O
in	O
peer-to-peer	O
(	O
P2P	O
)	O
services	O
and	O
networks	O
.	O
</s>
<s>
P2P	O
networks	O
usually	O
implement	O
overlay	B-Architecture
networks	I-Architecture
running	O
over	O
an	O
underlying	O
physical	O
or	O
logical	O
network	O
.	O
</s>
<s>
These	O
overlay	B-Architecture
networks	I-Architecture
may	O
implement	O
certain	O
organizational	O
structures	O
of	O
the	O
nodes	O
according	O
to	O
several	O
distinct	O
models	O
,	O
the	O
network	B-Architecture
architecture	I-Architecture
of	O
the	O
system	O
.	O
</s>
