<s>
topological	B-Architecture
design	O
,	O
network-synthesis	O
,	O
and	O
network-realization	O
,	O
and	O
is	O
aimed	O
at	O
ensuring	O
that	O
a	O
new	O
telecommunications	O
network	O
or	O
service	O
meets	O
the	O
needs	O
of	O
the	O
subscriber	O
and	O
operator	O
.	O
</s>
<s>
Topological	B-Architecture
design	O
:	O
This	O
stage	O
involves	O
determining	O
where	O
to	O
place	O
the	O
components	O
and	O
how	O
to	O
connect	O
them	O
.	O
</s>
<s>
The	O
(	O
topological	B-Architecture
)	O
optimization	O
methods	O
that	O
can	O
be	O
used	O
in	O
this	O
stage	O
come	O
from	O
an	O
area	O
of	O
mathematics	O
called	O
graph	O
theory	O
.	O
</s>
<s>
These	O
methods	O
involve	O
determining	O
the	O
costs	O
of	O
transmission	O
and	O
the	O
cost	O
of	O
switching	O
,	O
and	O
thereby	O
determining	O
the	O
optimum	O
connection	O
matrix	B-Architecture
and	O
location	O
of	O
switches	B-Protocol
and	O
concentrators	O
.	O
</s>
<s>
The	O
method	O
used	O
is	O
known	O
as	O
"	O
Nonlinear	O
Optimisation	O
"	O
,	O
and	O
involves	O
determining	O
the	O
topology	B-Architecture
,	O
required	O
GoS	O
,	O
cost	O
of	O
transmission	O
,	O
etc.	O
,	O
and	O
using	O
this	O
information	O
to	O
calculate	O
a	O
routing	O
plan	O
,	O
and	O
the	O
size	O
of	O
the	O
components	O
.	O
</s>
<s>
During	O
the	O
process	O
of	O
Network	B-Architecture
Planning	I-Architecture
and	I-Architecture
Design	I-Architecture
,	O
estimates	O
are	O
made	O
of	O
the	O
expected	O
traffic	O
intensity	O
and	O
traffic	B-Protocol
load	I-Protocol
that	O
the	O
network	O
must	O
support	O
.	O
</s>
<s>
If	O
a	O
network	O
of	O
a	O
similar	O
nature	O
already	O
exists	O
,	O
traffic	O
measurements	O
of	O
such	O
a	O
network	O
can	O
be	O
used	O
to	O
calculate	O
the	O
exact	O
traffic	B-Protocol
load	I-Protocol
.	O
</s>
<s>
The	O
dimensioning	O
process	O
involves	O
determining	O
the	O
network	O
’s	O
topology	B-Architecture
,	O
routing	O
plan	O
,	O
traffic	O
matrix	B-Architecture
,	O
and	O
GoS	O
requirements	O
,	O
and	O
using	O
this	O
information	O
to	O
determine	O
the	O
maximum	O
call	O
handling	O
capacity	O
of	O
the	O
switches	B-Protocol
,	O
and	O
the	O
maximum	O
number	O
of	O
channels	O
required	O
between	O
the	O
switches	B-Protocol
.	O
</s>
<s>
This	O
process	O
requires	O
a	O
complex	O
model	O
that	O
simulates	O
the	O
behavior	O
of	O
the	O
network	O
equipment	O
and	O
routing	B-Protocol
protocols	I-Protocol
.	O
</s>
<s>
A	O
dimensioning	O
rule	O
is	O
that	O
the	O
planner	O
must	O
ensure	O
that	O
the	O
traffic	B-Protocol
load	I-Protocol
should	O
never	O
approach	O
a	O
load	O
of	O
100	O
percent	O
.	O
</s>
<s>
Compared	O
to	O
network	O
engineering	O
,	O
which	O
adds	O
resources	O
such	O
as	O
links	O
,	O
routers	O
,	O
and	O
switches	B-Protocol
into	O
the	O
network	O
,	O
traffic	O
engineering	O
targets	O
changing	O
traffic	O
paths	O
on	O
the	O
existing	O
network	O
to	O
alleviate	O
traffic	O
congestion	O
or	O
accommodate	O
more	O
traffic	O
demand	O
.	O
</s>
<s>
It	O
has	O
been	O
one	O
of	O
the	O
critical	O
requirements	O
in	O
network	B-Architecture
planning	I-Architecture
and	I-Architecture
design	I-Architecture
.	O
</s>
<s>
It	O
involves	O
design	O
requirements	O
on	O
topology	B-Architecture
,	O
protocol	O
,	O
bandwidth	O
allocation	O
,	O
etc	O
..	O
Topology	B-Architecture
requirement	O
can	O
be	O
maintaining	O
a	O
minimum	O
two-connected	O
network	O
against	O
any	O
failure	O
of	O
a	O
single	O
link	O
or	O
node	O
.	O
</s>
<s>
Protocol	O
requirements	O
include	O
using	O
a	O
dynamic	O
routing	B-Protocol
protocol	I-Protocol
to	O
reroute	O
traffic	O
against	O
network	O
dynamics	O
during	O
the	O
transition	O
of	O
network	O
dimensioning	O
or	O
equipment	O
failures	O
.	O
</s>
