<s>
Mumble	B-Language
is	O
a	O
voice	B-Application
over	I-Application
IP	I-Application
(	O
VoIP	B-Application
)	O
application	O
primarily	O
designed	O
for	O
use	O
by	O
gamers	O
and	O
is	O
similar	O
to	O
programs	O
such	O
as	O
TeamSpeak	B-Language
.	O
</s>
<s>
Mumble	B-Language
uses	O
a	O
client	B-Operating_System
–	I-Operating_System
server	I-Operating_System
architecture	I-Operating_System
which	O
allows	O
users	O
to	O
talk	O
to	O
each	O
other	O
via	O
the	O
same	O
server	O
.	O
</s>
<s>
Mumble	B-Language
is	O
free	B-License
and	I-License
open-source	I-License
software	I-License
,	O
is	O
cross-platform	B-Operating_System
,	O
and	O
is	O
released	O
under	O
the	O
terms	O
of	O
the	O
BSD-3-Clause	B-Operating_System
license	O
.	O
</s>
<s>
A	O
Mumble	B-Language
server	O
(	O
called	O
Murmur	O
)	O
has	O
a	O
root	O
channel	O
and	O
a	O
hierarchical	O
tree	B-Data_Structure
of	O
channels	O
beneath	O
it	O
.	O
</s>
<s>
Mumble	B-Language
uses	O
the	O
low-latency	O
audio	O
codec	O
Opus	B-Algorithm
as	O
of	O
version	O
1.2.4	O
,	O
the	O
codec	O
that	O
succeeds	O
the	O
previous	O
defaults	O
Speex	B-Application
and	O
CELT	B-Algorithm
.	O
</s>
<s>
This	O
and	O
the	O
rest	O
of	O
Mumble	B-Language
's	O
design	O
allow	O
for	O
low-latency	O
communication	O
,	O
meaning	O
a	O
shorter	O
delay	O
between	O
when	O
something	O
is	O
said	O
on	O
one	O
end	O
and	O
when	O
it	O
's	O
heard	O
on	O
the	O
other	O
.	O
</s>
<s>
Mumble	B-Language
also	O
incorporates	O
echo	O
cancellation	O
to	O
reduce	O
echo	O
when	O
using	O
speakers	O
or	O
poor	O
quality	O
sound	O
hardware	O
.	O
</s>
<s>
Mumble	B-Language
connects	O
to	O
a	O
server	O
via	O
a	O
TLS	B-Protocol
control	O
channel	O
,	O
with	O
the	O
audio	O
travelling	O
via	O
UDP	B-Protocol
encrypted	O
with	O
AES	B-Algorithm
in	O
OCB	B-Algorithm
mode	I-Algorithm
.	O
</s>
<s>
As	O
of	O
1.2.9	O
Mumble	B-Language
now	O
prefers	O
ECDHE	B-Protocol
+	O
AES-GCM	B-Algorithm
cipher	O
suites	O
if	O
possible	O
,	O
providing	O
Perfect	O
Forward	O
Secrecy	O
.	O
</s>
<s>
As	O
of	O
version	O
1.2	O
,	O
the	O
overlay	O
works	O
with	O
most	O
Direct3D	B-Application
9/10	O
and	O
OpenGL	B-Application
applications	O
on	O
Windows	O
and	O
has	O
OpenGL	B-Application
support	O
for	O
Linux	B-Application
and	O
MacOSX	O
.	O
</s>
<s>
For	O
certain	O
games	O
,	O
Mumble	B-Language
modifies	O
the	O
audio	O
to	O
position	O
other	O
players	O
 '	O
voices	O
according	O
to	O
their	O
relative	O
position	O
in	O
the	O
game	O
.	O
</s>
<s>
To	O
realise	O
this	O
,	O
Mumble	B-Language
sends	O
each	O
player	O
's	O
in-game	O
position	O
to	O
players	O
in	O
the	O
same	O
game	O
with	O
every	O
audio	O
packet	O
.	O
</s>
<s>
Mumble	B-Language
can	O
gather	O
the	O
information	O
needed	O
to	O
do	O
this	O
in	O
two	O
ways	O
:	O
it	O
either	O
reads	O
the	O
needed	O
information	O
directly	O
out	O
of	O
the	O
memory	O
of	O
the	O
game	O
or	O
the	O
games	O
provide	O
it	O
themselves	O
via	O
the	O
so-called	O
link	O
plugin	O
interface	O
.	O
</s>
<s>
The	O
link	O
plugin	O
provides	O
games	O
with	O
a	O
way	O
to	O
expose	O
the	O
information	O
needed	O
for	O
positional	O
audio	O
themselves	O
by	O
including	O
a	O
small	O
piece	O
of	O
source	O
code	O
provided	O
by	O
the	O
Mumble	B-Language
project	O
.	O
</s>
<s>
Several	O
high-profile	O
games	O
have	O
implemented	O
this	O
functionality	O
including	O
many	O
of	O
Valve	O
's	O
Source	B-Application
Engine	I-Application
based	O
games	O
(	O
Team	B-Application
Fortress	I-Application
2	I-Application
,	O
Day	B-Application
of	I-Application
Defeat	I-Application
:	I-Application
Source	I-Application
,	O
Counter-Strike	B-Application
:	I-Application
Source	I-Application
,	O
Half-Life	B-Application
2	I-Application
:	I-Application
Deathmatch	I-Application
)	O
and	O
Guild	B-Protocol
Wars	I-Protocol
2	I-Protocol
.	O
</s>
<s>
Third-party	O
mobile	O
apps	O
are	O
available	O
for	O
Mumble	B-Language
,	O
such	O
as	O
,	O
Plumble	O
for	O
Android( 	O
,	O
,	O
Note	O
:	O
Discontinued	O
in	O
2016	O
)	O
,	O
and	O
Mumla	O
(	O
,	O
)	O
.	O
</s>
<s>
Mumble	B-Language
fits	O
into	O
existing	O
technological	O
and	O
social	O
structures	O
.	O
</s>
<s>
As	O
such	O
,	O
the	O
server	O
is	O
fully	O
remote	O
controllable	O
over	O
ZeroC	B-Operating_System
Ice	I-Operating_System
.	O
</s>
<s>
The	O
project	O
provides	O
a	O
number	O
of	O
sample	O
scripts	O
illustrating	O
the	O
abilities	O
of	O
the	O
interface	O
as	O
well	O
as	O
prefabricated	O
scripts	O
offering	O
features	O
like	O
authenticating	O
users	O
using	O
an	O
existing	O
phpBB	B-Application
or	O
Simple	B-Protocol
Machines	I-Protocol
Forum	I-Protocol
database	O
.	O
</s>
<s>
The	O
murmur	O
server	O
uses	O
port	B-Language
64738	I-Language
TCP	B-Protocol
and	O
UDP	B-Protocol
by	O
default	O
.	O
</s>
<s>
An	O
alternative	O
minimalist	O
implementation	O
of	O
the	O
mumble-server	O
(	O
Murmur	O
)	O
is	O
called	O
uMurmur	O
.	O
</s>
<s>
It	O
is	O
intended	O
for	O
installation	O
on	O
embedded	B-Architecture
devices	I-Architecture
with	O
limited	O
resources	O
,	O
such	O
as	O
,	O
for	O
example	O
,	O
residential	B-Application
gateways	I-Application
running	O
OpenWrt	B-Application
.	O
</s>
<s>
Like	O
many	O
other	O
VoIP	B-Application
clients	O
,	O
Mumble	B-Language
servers	O
can	O
be	O
both	O
rented	O
or	O
hosted	O
locally	O
.	O
</s>
<s>
Hosting	O
a	O
Mumble	B-Language
server	O
locally	O
requires	O
downloading	O
Murmur	O
(	O
included	O
as	O
an	O
option	O
in	O
the	O
Mumble	B-Language
installer	O
)	O
and	O
launching	O
it	O
.	O
</s>
