<s>
A	O
computer	B-Application
network	I-Application
diagram	I-Application
is	O
a	O
schematic	O
depicting	O
the	O
nodes	O
and	O
connections	O
amongst	O
nodes	O
in	O
a	O
computer	B-Architecture
network	I-Architecture
or	O
,	O
more	O
generally	O
,	O
any	O
telecommunications	O
network	O
.	O
</s>
<s>
Computer	B-Application
network	I-Application
diagrams	I-Application
form	O
an	O
important	O
part	O
of	O
network	O
documentation	O
.	O
</s>
<s>
For	O
example	O
,	O
in	O
the	O
hypothetical	O
local	B-General_Concept
area	I-General_Concept
network	I-General_Concept
pictured	O
to	O
the	O
right	O
,	O
three	O
personal	O
computers	O
and	O
a	O
server	O
are	O
connected	O
to	O
a	O
switch	B-Protocol
;	O
the	O
server	O
is	O
further	O
connected	O
to	O
a	O
printer	O
and	O
a	O
gateway	B-Application
router	I-Application
,	O
which	O
is	O
connected	O
via	O
a	O
WAN	O
link	O
to	O
the	O
Internet	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
sample	O
diagram	O
does	O
not	O
indicate	O
the	O
physical	O
type	O
of	O
connection	O
between	O
the	O
PCs	O
and	O
the	O
switch	B-Protocol
,	O
but	O
since	O
a	O
modern	O
LAN	B-General_Concept
is	O
depicted	O
,	O
Ethernet	O
may	O
be	O
assumed	O
.	O
</s>
<s>
At	O
the	O
LAN	B-General_Concept
level	O
,	O
individual	O
nodes	O
may	O
represent	O
individual	O
physical	O
devices	O
,	O
such	O
as	O
hubs	O
or	O
file	O
servers	O
,	O
while	O
at	O
the	O
WAN	O
level	O
,	O
individual	O
nodes	O
may	O
represent	O
entire	O
cities	O
.	O
</s>
<s>
In	O
addition	O
,	O
when	O
the	O
scope	O
of	O
a	O
diagram	O
crosses	O
the	O
common	O
LAN/MAN/WAN	O
boundaries	O
,	O
representative	O
hypothetical	O
devices	O
may	O
be	O
depicted	O
instead	O
of	O
showing	O
all	O
actually	O
existing	O
nodes	O
.	O
</s>
<s>
Since	O
Cisco	O
has	O
a	O
large	O
Internet	O
presence	O
and	O
designs	O
a	O
broad	O
variety	O
of	O
network	O
devices	O
,	O
its	O
list	O
of	O
symbols	O
(	O
"	O
Network	B-Architecture
Topology	I-Architecture
Icons	O
"	O
)	O
is	O
exhaustive	O
.	O
</s>
<s>
The	O
physical	O
network	B-Architecture
topology	I-Architecture
can	O
be	O
directly	O
represented	O
in	O
a	O
network	O
diagram	O
,	O
as	O
it	O
is	O
simply	O
the	O
physical	O
graph	O
represented	O
by	O
the	O
diagrams	O
,	O
with	O
network	O
nodes	O
as	O
vertices	O
and	O
connections	O
as	O
undirected	O
or	O
direct	O
edges	O
(	O
depending	O
on	O
the	O
type	O
of	O
connection	O
)	O
.	O
</s>
<s>
The	O
logical	O
network	B-Architecture
topology	I-Architecture
can	O
be	O
inferred	O
from	O
the	O
network	O
diagram	O
if	O
details	O
of	O
the	O
network	O
protocols	O
in	O
use	O
are	O
also	O
given	O
.	O
</s>
