<s>
Software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
(	O
SDDC	O
;	O
also	O
:	O
virtual	O
data	B-Operating_System
center	I-Operating_System
,	O
VDC	O
)	O
is	O
a	O
marketing	O
term	O
that	O
extends	O
virtualization	B-General_Concept
concepts	O
such	O
as	O
abstraction	O
,	O
pooling	O
,	O
and	O
automation	O
to	O
all	O
data	B-Operating_System
center	I-Operating_System
resources	O
and	O
services	O
to	O
achieve	O
IT	B-Application
as	I-Application
a	I-Application
service	I-Application
(	O
ITaaS	B-Application
)	O
.	O
</s>
<s>
In	O
a	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
,	O
"	O
all	O
elements	O
of	O
the	O
infrastructure	O
—	O
networking	O
,	O
storage	O
,	O
CPU	O
and	O
security	O
–	O
are	O
virtualized	B-General_Concept
and	O
delivered	O
as	O
a	O
service.	O
"	O
</s>
<s>
Critics	O
see	O
the	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
as	O
a	O
marketing	O
tool	O
and	O
"	O
software-defined	O
hype	O
,	O
"	O
noting	O
this	O
variability	O
.	O
</s>
<s>
In	O
2013	O
,	O
an	O
analyst	O
projected	O
that	O
at	O
least	O
some	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
components	O
would	O
experience	O
market	O
growth	O
.	O
</s>
<s>
The	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
encompasses	O
a	O
variety	O
of	O
concepts	O
and	O
data-center	B-Operating_System
infrastructure	O
components	O
,	O
with	O
each	O
component	O
potentially	O
provisioned	O
,	O
operated	O
,	O
and	O
managed	O
through	O
an	O
application	B-Application
programming	I-Application
interface	I-Application
(	O
API	B-Application
)	O
.	O
</s>
<s>
Core	O
architectural	O
components	O
that	O
comprise	O
the	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
include	O
the	O
following	O
:	O
</s>
<s>
A	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
differs	O
from	O
a	O
private	O
cloud	O
,	O
since	O
a	O
private	O
cloud	O
only	O
has	O
to	O
offer	O
virtual-machine	B-Architecture
self-service	O
,	O
beneath	O
which	O
it	O
could	O
use	O
traditional	O
provisioning	O
and	O
management	O
.	O
</s>
<s>
Instead	O
,	O
SDDC	O
concepts	O
imagine	O
a	O
data	B-Operating_System
center	I-Operating_System
that	O
can	O
encompass	O
private	O
,	O
public	O
,	O
and	O
hybrid	O
clouds	O
.	O
</s>
<s>
Data	B-Operating_System
centers	I-Operating_System
traditionally	O
lacked	O
the	O
capacity	O
to	O
accommodate	O
total	O
virtualization	B-General_Concept
.	O
</s>
<s>
By	O
2013	O
,	O
companies	O
began	O
laying	O
the	O
foundation	O
for	O
software-defined	B-General_Concept
data	I-General_Concept
centers	I-General_Concept
with	O
virtualization	B-General_Concept
.	O
</s>
<s>
Ben	O
Cherian	O
of	O
Midokura	O
considered	O
Amazon	B-Application
Web	I-Application
Services	I-Application
as	O
a	O
catalyst	O
for	O
the	O
move	O
toward	O
software-defined	B-General_Concept
data	I-General_Concept
centers	I-General_Concept
because	O
it	O
"	O
convinced	O
the	O
world	O
that	O
the	O
data	B-Operating_System
center	I-Operating_System
could	O
be	O
abstracted	O
into	O
much	O
smaller	O
units	O
and	O
could	O
be	O
treated	O
as	O
disposable	O
pieces	O
of	O
technology	O
,	O
which	O
in	O
turn	O
could	O
be	O
priced	O
as	O
a	O
utility.	O
"	O
</s>
<s>
In	O
2013	O
,	O
the	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
term	O
was	O
promoted	O
as	O
a	O
paradigm	O
shift	O
.	O
</s>
<s>
According	O
to	O
Steve	O
Herrod	O
,	O
the	O
promise	O
of	O
the	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
was	O
that	O
companies	O
would	O
no	O
longer	O
need	O
to	O
rely	O
on	O
specialized	O
hardware	O
or	O
hire	O
consultants	O
to	O
install	O
and	O
program	O
hardware	O
in	O
its	O
specialized	O
language	O
.	O
</s>
<s>
Commonly	O
cited	O
benefits	O
of	O
software-defined	B-General_Concept
data	I-General_Concept
centers	I-General_Concept
include	O
improved	O
efficiency	O
from	O
extending	O
virtualization	B-General_Concept
throughout	O
the	O
data	B-Operating_System
center	I-Operating_System
;	O
increased	O
agility	O
from	O
provisioning	O
applications	O
quickly	O
;	O
improved	O
control	O
over	O
application	O
availability	O
and	O
security	O
through	O
policy-based	O
governance	O
;	O
and	O
the	O
flexibility	O
to	O
run	O
new	O
and	O
existing	O
applications	O
in	O
multiple	O
platforms	O
and	O
clouds	O
.	O
</s>
<s>
In	O
addition	O
,	O
a	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
implementation	O
could	O
reduce	O
a	O
company	O
's	O
energy	O
usage	O
by	O
enabling	O
servers	O
and	O
other	O
data	B-Operating_System
center	I-Operating_System
hardware	O
to	O
run	O
at	O
decreased	O
power	O
levels	O
or	O
be	O
turned	O
off	O
.	O
</s>
<s>
Some	O
believe	O
that	O
software-defined	B-General_Concept
data	I-General_Concept
centers	I-General_Concept
improve	O
security	O
by	O
giving	O
organizations	O
more	O
control	O
over	O
their	O
hosted	O
data	O
and	O
security	O
levels	O
,	O
compared	O
to	O
security	O
provided	O
by	O
hosted-cloud	O
providers	O
.	O
</s>
<s>
The	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
was	O
marketed	O
to	O
drive	O
down	O
prices	O
for	O
data	B-Operating_System
center	I-Operating_System
hardware	O
and	O
challenge	O
traditional	O
hardware	O
vendors	O
to	O
develop	O
new	O
ways	O
to	O
differentiate	O
their	O
products	O
through	O
software	O
and	O
services	O
.	O
</s>
<s>
The	O
concepts	O
of	O
software-defined	O
in	O
general	O
,	O
and	O
software-defined	B-General_Concept
data	I-General_Concept
centers	I-General_Concept
in	O
particular	O
,	O
have	O
been	O
dismissed	O
by	O
some	O
as	O
“	O
nonsense	O
,	O
”	O
“	O
marketecture	O
,	O
”	O
and	O
“	O
software-defined	O
hype.	O
”	O
Some	O
critics	O
believe	O
that	O
only	O
a	O
minority	O
of	O
companies	O
with	O
“	O
completely	O
homogeneous	O
IT	O
systems’”	O
already	O
in	O
place	O
,	O
such	O
as	O
Yahoo	B-Application
!	I-Application
</s>
<s>
and	O
Google	B-Application
,	O
can	O
transition	O
to	O
software-defined	B-General_Concept
data	I-General_Concept
centers	I-General_Concept
.	O
</s>
<s>
According	O
to	O
some	O
observers	O
,	O
software-defined	B-General_Concept
data	I-General_Concept
centers	I-General_Concept
wo	O
n’t	O
necessarily	O
eliminate	O
challenges	O
that	O
relate	O
to	O
handling	O
the	O
differences	O
between	O
development	O
and	O
production	O
environments	O
;	O
managing	O
a	O
mix	O
of	O
legacy	O
and	O
new	O
applications	O
;	O
or	O
delivering	O
service-level	O
agreements	O
(	O
SLAs	O
)	O
.	O
</s>
<s>
Software-defined	O
networking	O
was	O
seen	O
as	O
essential	O
to	O
the	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
,	O
but	O
it	O
is	O
also	O
considered	O
to	O
be	O
the	O
“	O
least	O
mature	O
technology	O
”	O
required	O
to	O
enable	O
the	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
.	O
</s>
<s>
However	O
,	O
several	O
companies	O
,	O
including	O
Arista	O
Networks	O
,	O
Cisco	O
,	O
Microsoft	O
and	O
VMware	O
,	O
market	O
products	O
to	O
enable	O
virtual	B-Protocol
networks	I-Protocol
that	O
are	O
provisioned	O
,	O
extended	O
,	O
and	O
moved	O
across	O
existing	O
physical	O
networks	O
.	O
</s>
<s>
Several	O
competing	O
network	B-Protocol
virtualization	I-Protocol
standards	O
already	O
existed	O
by	O
2012	O
.	O
</s>
<s>
Neutron	O
,	O
the	O
networking	O
component	O
of	O
the	O
open-source	B-Application
software	I-Application
OpenStack	B-Application
project	O
,	O
provides	O
an	O
application-level	O
abstraction	O
of	O
network	O
resources	O
and	O
includes	O
an	O
interface	O
for	O
configuring	O
virtual	O
switches	O
.	O
</s>
<s>
The	O
software-defined	B-General_Concept
data	I-General_Concept
center	I-General_Concept
approach	O
will	O
force	O
IT	O
organizations	O
to	O
adapt	O
.	O
</s>
