<s>
Open	B-Language
vSwitch	I-Language
,	O
sometimes	O
abbreviated	O
as	O
OVS	O
,	O
is	O
an	O
open-source	B-Application
implementation	O
of	O
a	O
distributed	B-Language
virtual	I-Language
multilayer	I-Language
switch	I-Language
.	O
</s>
<s>
The	O
main	O
purpose	O
of	O
Open	B-Language
vSwitch	I-Language
is	O
to	O
provide	O
a	O
switching	B-Protocol
stack	O
for	O
hardware	B-General_Concept
virtualization	I-General_Concept
environments	O
,	O
while	O
supporting	O
multiple	O
protocols	O
and	O
standards	O
used	O
in	O
computer	B-Architecture
networks	I-Architecture
.	O
</s>
<s>
Open	B-Language
vSwitch	I-Language
is	O
a	O
software	O
implementation	O
of	O
a	O
virtual	B-General_Concept
multilayer	O
network	B-Protocol
switch	I-Protocol
,	O
designed	O
to	O
enable	O
effective	O
network	O
automation	O
through	O
programmatic	O
extensions	O
,	O
while	O
supporting	O
standard	O
management	O
interfaces	O
and	O
protocols	O
such	O
as	O
NetFlow	B-Protocol
,	O
sFlow	O
,	O
SPAN	B-Protocol
,	O
RSPAN	B-Protocol
,	O
CLI	B-Application
,	O
LACP	O
and	O
802.1ag	O
.	O
</s>
<s>
In	O
addition	O
,	O
Open	B-Language
vSwitch	I-Language
is	O
designed	O
to	O
support	O
transparent	O
distribution	O
across	O
multiple	O
physical	O
servers	O
by	O
enabling	O
creation	O
of	O
cross-server	O
switches	O
in	O
a	O
way	O
that	O
abstracts	O
out	O
the	O
underlying	O
server	B-Application
architecture	O
,	O
similar	O
to	O
the	O
VMware	O
vNetwork	O
distributed	O
vswitch	O
or	O
Cisco	O
Nexus	O
1000V	O
.	O
</s>
<s>
Open	B-Language
vSwitch	I-Language
can	O
operate	O
both	O
as	O
a	O
software-based	O
network	B-Protocol
switch	I-Protocol
running	O
within	O
a	O
virtual	B-Architecture
machine	I-Architecture
(	O
VM	O
)	O
hypervisor	B-Operating_System
,	O
and	O
as	O
the	O
control	O
stack	O
for	O
dedicated	O
switching	B-Protocol
hardware	O
;	O
as	O
a	O
result	O
,	O
it	O
has	O
been	O
ported	O
to	O
multiple	O
virtualization	B-General_Concept
platforms	O
,	O
switching	B-Protocol
chipsets	O
,	O
and	O
networking	O
hardware	B-General_Concept
accelerators	I-General_Concept
.	O
</s>
<s>
Open	B-Language
vSwitch	I-Language
is	O
the	O
default	O
network	B-Protocol
switch	I-Protocol
in	O
the	O
XenServer	B-Operating_System
virtualization	B-General_Concept
platform	O
since	O
its	O
version	O
6.0	O
,	O
and	O
in	O
the	O
Xen	B-Operating_System
Cloud	I-Operating_System
Platform	I-Operating_System
via	O
its	O
XAPI	B-Operating_System
management	O
toolstack	O
.	O
</s>
<s>
It	O
also	O
supports	O
Xen	B-Operating_System
,	O
Linux	B-Application
KVM	I-Application
,	O
Proxmox	O
VE	O
and	O
VirtualBox	B-Operating_System
hypervisors	B-Operating_System
,	O
while	O
a	O
port	O
to	O
Hyper-V	O
is	O
also	O
available	O
.	O
</s>
<s>
Open	B-Language
vSwitch	I-Language
has	O
also	O
been	O
integrated	O
into	O
various	O
cloud	B-Architecture
computing	I-Architecture
software	O
platforms	O
and	O
virtualization	B-General_Concept
management	O
systems	O
,	O
including	O
OpenStack	B-Application
,	O
openQRM	B-General_Concept
,	O
OpenNebula	B-Language
and	O
oVirt	B-Language
.	O
</s>
<s>
The	O
Linux	B-Operating_System
kernel	I-Operating_System
implementation	O
of	O
Open	B-Language
vSwitch	I-Language
was	O
merged	O
into	O
the	O
kernel	B-Operating_System
mainline	O
in	O
kernel	B-Operating_System
version	O
3.3	O
,	O
which	O
was	O
released	O
on	O
March	O
18	O
,	O
2012	O
;	O
official	O
Linux	B-Operating_System
packages	O
are	O
available	O
for	O
Debian	O
,	O
Fedora	O
,	O
openSUSE	B-Operating_System
and	O
Ubuntu	B-Operating_System
.	O
</s>
<s>
,	O
FreeBSD	B-Operating_System
and	O
NetBSD	B-Device
implementations	O
are	O
also	O
available	O
,	O
with	O
the	O
NetBSD	B-Device
's	O
implementation	O
operating	O
completely	O
in	O
userspace	B-Operating_System
.	O
</s>
<s>
The	O
majority	O
of	O
the	O
Open	B-Language
vSwitch	I-Language
source	O
code	O
is	O
written	O
in	O
platform-independent	O
C	B-Language
language	I-Language
,	O
which	O
provides	O
easy	O
portability	O
to	O
various	O
environments	O
.	O
</s>
<s>
The	O
source	O
code	O
is	O
licensed	O
under	O
the	O
Apache	B-Application
License	I-Application
2.0	I-Application
.	O
</s>
<s>
,	O
features	O
provided	O
by	O
Open	B-Language
vSwitch	I-Language
include	O
the	O
following	O
:	O
</s>
