<s>
WAN	B-Protocol
optimization	I-Protocol
is	O
a	O
collection	O
of	O
techniques	O
for	O
improving	O
data	O
transfer	O
across	O
wide	O
area	O
networks	O
(	O
WANs	O
)	O
.	O
</s>
<s>
In	O
2008	O
,	O
the	O
WAN	B-Protocol
optimization	I-Protocol
market	O
was	O
estimated	O
to	O
be	O
$1	O
billion	O
,	O
and	O
was	O
to	O
grow	O
to	O
$4.4	O
billion	O
by	O
2014	O
according	O
to	O
Gartner	O
,	O
a	O
technology	O
research	O
firm	O
.	O
</s>
<s>
In	O
2015	O
Gartner	O
estimated	O
the	O
WAN	B-Protocol
optimization	I-Protocol
market	O
to	O
be	O
a	O
$1.1	O
billion	O
market	O
.	O
</s>
<s>
Two	O
common	O
business	O
WAN	O
topologies	O
are	O
Branch	O
to	O
Headquarters	O
and	O
Data	B-Operating_System
Center	I-Operating_System
to	O
Data	B-Operating_System
Center	I-Operating_System
(	O
DC2DC	O
)	O
.	O
</s>
<s>
Traffic	O
on	O
a	O
"	O
DC2DC	O
"	O
WAN	O
may	O
include	O
replication	O
,	O
back	O
up	O
,	O
data	B-General_Concept
migration	I-General_Concept
,	O
virtualization	O
,	O
and	O
other	O
Business	O
Continuity/Disaster	O
Recovery	O
(	O
BC/DR	O
)	O
flows	O
.	O
</s>
<s>
WAN	B-Protocol
optimization	I-Protocol
has	O
been	O
the	O
subject	O
of	O
extensive	O
academic	O
research	O
almost	O
since	O
the	O
advent	O
of	O
the	O
WAN	O
.	O
</s>
<s>
In	O
the	O
early	O
2000s	O
,	O
research	O
in	O
both	O
the	O
private	O
and	O
public	O
sectors	O
turned	O
to	O
improving	O
the	O
end-to-end	O
throughput	O
of	O
TCP	O
,	O
and	O
the	O
target	O
of	O
the	O
first	O
proprietary	B-Application
WAN	B-Protocol
optimization	I-Protocol
solutions	O
was	O
the	O
Branch	O
WAN	O
.	O
</s>
<s>
In	O
recent	O
years	O
,	O
however	O
,	O
the	O
rapid	O
growth	O
of	O
digital	O
data	O
,	O
and	O
the	O
concomitant	O
needs	O
to	O
store	O
and	O
protect	O
it	O
,	O
has	O
presented	O
a	O
need	O
for	O
DC2DC	O
WAN	B-Protocol
optimization	I-Protocol
.	O
</s>
<s>
For	O
example	O
,	O
such	O
optimizations	O
can	O
be	O
performed	O
to	O
increase	O
overall	O
network	O
capacity	O
utilization	O
,	O
meet	O
inter-datacenter	O
transfer	O
deadlines	O
,	O
or	O
minimize	O
average	O
completion	O
times	O
of	O
data	O
transfers	O
.	O
</s>
<s>
As	O
another	O
example	O
,	O
private	O
inter-datacenter	O
WANs	O
can	O
benefit	O
optimizations	O
for	O
fast	O
and	O
efficient	O
geo-replication	O
of	O
data	O
and	O
content	O
,	O
such	O
as	O
newly	O
computed	O
machine	O
learning	O
models	O
or	O
multimedia	O
content	O
.	O
</s>
<s>
Component	O
techniques	O
of	O
Branch	O
WAN	B-Protocol
Optimization	I-Protocol
include	O
deduplication	B-General_Concept
,	O
wide	B-General_Concept
area	I-General_Concept
file	I-General_Concept
services	I-General_Concept
(	O
WAFS	O
)	O
,	O
SMB	B-Operating_System
proxy	O
,	O
HTTPS	B-Application
Proxy	I-Application
,	O
media	O
multicasting	O
,	O
web	B-Protocol
caching	I-Protocol
,	O
and	O
bandwidth	O
management	O
.	O
</s>
<s>
Requirements	O
for	O
DC2DC	O
WAN	B-Protocol
Optimization	I-Protocol
also	O
center	O
around	O
deduplication	B-General_Concept
and	O
TCP	O
acceleration	O
,	O
however	O
these	O
must	O
occur	O
in	O
the	O
context	O
of	O
multi-gigabit	O
data	O
transfer	O
rates	O
.	O
</s>
<s>
Essentially	O
compression	B-General_Concept
techniques	I-General_Concept
similar	O
to	O
ZIP	O
,	O
RAR	O
,	O
ARJ	O
etc	O
.	O
</s>
<s>
Staging	O
data	O
in	O
local	O
caches	B-Protocol
;	O
Relies	O
on	O
human	O
behavior	O
,	O
accessing	O
the	O
same	O
data	O
over	O
and	O
over	O
.	O
</s>
<s>
May	O
also	O
include	O
stream-lining	O
protocols	O
such	O
as	O
CIFS	B-Operating_System
.	O
</s>
