<s>
In	O
cloud	B-Architecture
computing	I-Architecture
a	O
carrier	B-General_Concept
cloud	I-General_Concept
is	O
a	O
class	O
of	O
cloud	O
that	O
integrates	O
wide	O
area	O
networks	O
(	O
WAN	O
)	O
and	O
other	O
attributes	O
of	O
communications	O
service	O
providers’	O
carrier	O
grade	O
networks	O
to	O
enable	O
the	O
deployment	O
of	O
highly	O
complex	O
applications	O
in	B-Architecture
the	I-Architecture
cloud	I-Architecture
.	O
</s>
<s>
In	O
contrast	O
,	O
classic	O
cloud	B-Architecture
computing	I-Architecture
focuses	O
on	O
the	O
data	O
centre	O
,	O
and	O
does	O
not	O
address	O
the	O
network	O
connecting	O
data	O
centres	O
and	O
cloud	B-Architecture
users	I-Architecture
.	O
</s>
<s>
The	O
advent	O
of	O
virtualization	B-General_Concept
technology	I-General_Concept
and	O
cost	O
effective	O
computing	O
hardware	O
as	O
well	O
as	O
ubiquitous	O
Internet	O
connectivity	O
enabled	O
the	O
first	O
wave	O
of	O
cloud	B-Architecture
services	I-Architecture
starting	O
in	O
the	O
early	O
years	O
of	O
the	O
21st	O
century	O
.	O
</s>
<s>
As	O
a	O
response	O
,	O
communications	O
service	O
providers	O
started	O
in	O
the	O
2010/2011	O
time	O
frame	O
to	O
develop	O
carrier	B-General_Concept
clouds	I-General_Concept
that	O
address	O
perceived	O
weaknesses	O
in	O
existing	O
cloud	B-Architecture
services	I-Architecture
.	O
</s>
<s>
To	O
enable	O
the	O
deployment	O
of	O
time-sensitive	O
and	O
business	O
critical	O
applications	O
in	B-Architecture
the	I-Architecture
cloud	I-Architecture
,	O
the	O
carrier	B-General_Concept
cloud	I-General_Concept
is	O
designed	O
to	O
match	O
or	O
even	O
exceed	O
the	O
characteristics	O
of	O
on-premises	O
deployments	O
.	O
</s>
<s>
Therefore	O
,	O
the	O
carrier	B-General_Concept
cloud	I-General_Concept
is	O
characterized	O
by	O
some	O
or	O
all	O
of	O
the	O
following	O
items	O
:	O
</s>
<s>
Configurable	O
,	O
elastic	O
network	O
performance	O
:	O
Typical	O
cloud	B-Architecture
computing	I-Architecture
solutions	O
use	O
the	O
best	O
effort	O
public	O
Internet	O
to	O
connect	O
cloud	B-Architecture
users	I-Architecture
and	O
data	O
centres	O
.	O
</s>
<s>
Carrier	B-General_Concept
clouds	I-General_Concept
address	O
these	O
gaps	O
with	O
content	B-Operating_System
delivery	I-Operating_System
networks	I-Operating_System
and/or	O
dedicated	O
virtual	B-Application
private	I-Application
networks	I-Application
(	O
VPN	B-Application
)	O
at	O
OSI	O
layers	O
1	O
(	O
optical	O
wavelengths	B-Architecture
)	O
,	O
2	O
(	O
data	B-Protocol
link	I-Protocol
layer	I-Protocol
)	O
,	O
and	O
3	O
(	O
network	B-Application
layer	I-Application
)	O
.	O
</s>
<s>
These	O
VPNs	B-Application
can	O
be	O
configured	O
to	O
offer	O
the	O
desired	O
performance	O
parameters	O
and	O
exhibit	O
the	O
same	O
type	O
of	O
elasticity	O
for	O
the	O
network	O
that	O
regular	O
clouds	O
provide	O
for	O
servers	O
and	O
storage	O
.	O
</s>
<s>
To	O
achieve	O
the	O
requested	O
performance	O
parameters	O
,	O
such	O
as	O
low	O
latency	O
,	O
cloud	B-Architecture
applications	I-Architecture
can	O
be	O
(	O
automatically	O
)	O
allocated	O
to	O
distributed	O
data	O
centres	O
that	O
are	O
close	O
enough	O
to	O
the	O
cloud	B-Architecture
users	I-Architecture
.	O
</s>
<s>
For	O
this	O
decision	O
,	O
carrier	B-General_Concept
clouds	I-General_Concept
can	O
obtain	O
relevant	O
information	O
about	O
the	O
network	O
,	O
e.g.	O
,	O
using	O
the	O
Application-Layer	O
Traffic	O
Optimization	O
(	O
ALTO	O
)	O
protocol	O
.	O
</s>
<s>
For	O
added	O
security	O
,	O
the	O
wide	O
area	O
network	O
of	O
the	O
carrier	B-General_Concept
cloud	I-General_Concept
can	O
provide	O
segregated	O
encrypted	O
or	O
unencrypted	O
network	O
links	O
that	O
are	O
not	O
accessible	O
from	O
the	O
general	O
Internet	O
.	O
</s>
<s>
At	O
the	O
data	O
centre	O
,	O
the	O
carrier	B-General_Concept
cloud	I-General_Concept
provides	O
e.g.	O
</s>
<s>
Location	O
control	O
:	O
Fundamentally	O
,	O
cloud	B-Architecture
users	I-Architecture
should	O
not	O
be	O
concerned	O
with	O
the	O
geographic	O
location	O
of	O
their	O
cloud	O
resources	O
.	O
</s>
<s>
Open	O
APIs	O
:	O
Carrier	B-General_Concept
clouds	I-General_Concept
provide	O
graphical	B-Application
user	I-Application
interfaces	I-Application
and	O
Web	O
application	O
programming	O
interfaces	O
that	O
allow	O
cloud	O
application	O
providers	O
to	O
set	O
up	O
,	O
manage	O
,	O
and	O
monitor	O
both	O
,	O
the	O
data	O
centre	O
and	O
the	O
WAN	O
,	O
of	O
their	O
cloud	B-Architecture
services	I-Architecture
.	O
</s>
<s>
Carrier	B-General_Concept
clouds	I-General_Concept
encompass	O
data	O
centre	O
at	O
different	O
network	O
tiers	O
and	O
wide	O
area	O
networks	O
that	O
connect	O
multiple	O
data	O
centers	O
to	O
each	O
other	O
as	O
well	O
as	O
to	O
the	O
cloud	B-Architecture
users	I-Architecture
.	O
</s>
<s>
Carrier	B-General_Concept
clouds	I-General_Concept
can	O
be	O
set	O
up	O
as	O
public	O
,	O
private	O
,	O
or	O
hybrid	O
clouds	O
.	O
</s>
<s>
The	O
carrier	B-General_Concept
cloud	I-General_Concept
federates	O
these	O
cloud	O
entities	O
,	O
using	O
a	O
single	O
management	O
system	O
to	O
orchestrate	O
,	O
manage	O
,	O
and	O
monitor	O
data	O
centre	O
and	O
network	O
resources	O
as	O
a	O
single	O
system	O
.	O
</s>
