<s>
WebRTC	B-Protocol
(	O
Web	O
Real-Time	B-Protocol
Communication	I-Protocol
)	O
is	O
a	O
free	B-License
and	I-License
open-source	I-License
project	O
providing	O
web	B-Application
browsers	I-Application
and	O
mobile	B-Application
applications	I-Application
with	O
real-time	B-Protocol
communication	I-Protocol
(	O
RTC	O
)	O
via	O
application	B-Application
programming	I-Application
interfaces	I-Application
(	O
APIs	B-Application
)	O
.	O
</s>
<s>
It	O
allows	O
audio	O
and	O
video	O
communication	O
to	O
work	O
inside	O
web	O
pages	O
by	O
allowing	O
direct	O
peer-to-peer	O
communication	O
,	O
eliminating	O
the	O
need	O
to	O
install	O
plugins	B-Application
or	O
download	O
native	O
apps	O
.	O
</s>
<s>
Supported	O
by	O
Apple	O
,	O
Google	B-Application
,	O
Microsoft	O
,	O
Mozilla	B-Operating_System
,	O
and	O
Opera	B-Application
,	O
WebRTC	B-Protocol
specifications	O
have	O
been	O
published	O
by	O
the	O
World	O
Wide	O
Web	O
Consortium	O
(	O
W3C	O
)	O
and	O
the	O
Internet	O
Engineering	O
Task	O
Force	O
(	O
IETF	O
)	O
.	O
</s>
<s>
According	O
to	O
the	O
webrtc.org	O
website	O
,	O
the	O
purpose	O
of	O
the	O
project	O
is	O
to	O
"	O
enable	O
rich	O
,	O
high-quality	O
RTC	O
applications	O
to	O
be	O
developed	O
for	O
the	O
browser	B-Application
,	O
mobile	O
platforms	O
,	O
and	O
IoT	B-Operating_System
devices	I-Operating_System
,	O
and	O
allow	O
them	O
all	O
to	O
communicate	O
via	O
a	O
common	O
set	O
of	O
protocols	O
"	O
.	O
</s>
<s>
In	O
May	O
2010	O
,	O
Google	B-Application
bought	O
Global	B-Application
IP	I-Application
Solutions	I-Application
or	O
GIPS	O
,	O
a	O
VoIP	B-Application
and	O
videoconferencing	B-Application
software	O
company	O
that	O
had	O
developed	O
many	O
components	O
required	O
for	O
RTC	O
,	O
such	O
as	O
codecs	B-General_Concept
and	O
echo	O
cancellation	O
techniques	O
.	O
</s>
<s>
Google	B-Application
open-sourced	O
the	O
GIPS	O
technology	O
and	O
engaged	O
with	O
relevant	O
standards	O
bodies	O
at	O
the	O
IETF	O
and	O
W3C	O
to	O
ensure	O
industry	O
consensus	O
.	O
</s>
<s>
In	O
May	O
2011	O
,	O
Google	B-Application
released	O
an	O
open-source	B-Application
project	O
for	O
browser-based	O
real-time	B-Protocol
communication	I-Protocol
known	O
as	O
WebRTC	B-Protocol
.	O
</s>
<s>
This	O
has	O
been	O
followed	O
by	O
ongoing	O
work	O
to	O
standardize	O
the	O
relevant	O
protocols	O
in	O
the	O
IETF	O
and	O
browser	B-Application
APIs	B-Application
in	O
the	O
W3C	O
.	O
</s>
<s>
In	O
January	O
2011	O
,	O
Ericsson	O
Labs	O
built	O
the	O
first	O
implementation	O
of	O
WebRTC	B-Protocol
using	O
a	O
modified	O
WebKit	B-Language
library	O
.	O
</s>
<s>
WebRTC	B-Protocol
milestones	O
include	O
the	O
first	O
cross-browser	O
video	B-Application
call	I-Application
(	O
February	O
2013	O
)	O
,	O
first	O
cross-browser	O
data	O
transfers	O
(	O
February	O
2014	O
)	O
,	O
and	O
as	O
of	O
July	O
2014	O
Google	B-Protocol
Hangouts	I-Protocol
was	O
"	O
kind	O
of	O
"	O
using	O
WebRTC	B-Protocol
.	O
</s>
<s>
The	O
W3C	O
draft	O
API	B-Application
was	O
based	O
on	O
preliminary	O
work	O
done	O
in	O
the	O
WHATWG	B-Language
.	O
</s>
<s>
It	O
was	O
referred	O
to	O
as	O
the	O
ConnectionPeer	O
API	B-Application
,	O
and	O
a	O
pre-standards	O
concept	O
implementation	O
was	O
created	O
at	O
Ericsson	O
Labs	O
.	O
</s>
<s>
The	O
WebRTC	B-Protocol
Working	O
Group	O
expects	O
this	O
specification	O
to	O
evolve	O
significantly	O
based	O
on	O
:	O
</s>
<s>
Outcomes	O
of	O
ongoing	O
exchanges	O
in	O
the	O
companion	O
RTCWEB	O
group	O
at	O
IETF	O
to	O
define	O
the	O
set	O
of	O
protocols	O
that	O
,	O
together	O
with	O
this	O
document	O
,	O
define	O
real-time	B-Protocol
communications	I-Protocol
in	O
web	B-Application
browsers	I-Application
.	O
</s>
<s>
While	O
no	O
one	O
signaling	O
protocol	O
is	O
mandated	O
,	O
SIP	B-Application
over	O
WebSockets	B-Protocol
(	O
)	O
is	O
often	O
used	O
partially	O
due	O
to	O
the	O
applicability	O
of	O
SIP	B-Application
to	O
most	O
of	O
the	O
envisaged	O
communication	O
scenarios	O
as	O
well	O
as	O
the	O
availability	O
of	O
open-source	B-Application
software	I-Application
such	O
as	O
JsSIP	B-Language
.	O
</s>
<s>
In	O
November	O
2017	O
,	O
the	O
WebRTC	B-Protocol
1.0	I-Protocol
specification	O
transitioned	O
from	O
Working	O
Draft	O
to	O
Candidate	O
Recommendation	O
.	O
</s>
<s>
In	O
January	O
2021	O
,	O
the	O
WebRTC	B-Protocol
1.0	I-Protocol
specification	O
transitioned	O
from	O
Candidate	O
Recommendation	O
to	O
Recommendation	O
.	O
</s>
<s>
Major	O
components	O
of	O
WebRTC	B-Protocol
include	O
several	O
JavaScript	B-Language
APIs	B-Application
:	O
</s>
<s>
It	O
performs	O
signal	O
processing	O
,	O
codec	B-General_Concept
handling	O
,	O
peer-to-peer	O
communication	O
,	O
security	B-Application
,	O
and	O
bandwidth	O
management	O
.	O
</s>
<s>
The	O
data	O
is	O
transported	O
using	O
SCTP	B-Protocol
over	O
DTLS	B-General_Concept
.	O
</s>
<s>
It	O
uses	O
the	O
same	O
API	B-Application
as	O
WebSockets	B-Protocol
and	O
has	O
very	O
low	O
latency	B-Protocol
.	O
</s>
<s>
The	O
WebRTC	B-Protocol
API	B-Application
also	O
includes	O
a	O
statistics	O
function	O
:	O
</s>
<s>
getStats	O
allows	O
the	O
web	O
application	O
to	O
retrieve	O
a	O
set	O
of	O
statistics	O
about	O
WebRTC	B-Protocol
sessions	O
.	O
</s>
<s>
The	O
WebRTC	B-Protocol
API	B-Application
includes	O
no	O
provisions	O
for	O
signaling	O
,	O
that	O
is	O
discovering	O
peers	O
to	O
connect	O
to	O
and	O
determine	O
how	O
to	O
establish	O
connections	O
among	O
them	O
.	O
</s>
<s>
Applications	O
use	O
Interactive	O
Connectivity	O
Establishment	O
for	O
connections	O
and	O
are	O
responsible	O
for	O
managing	O
sessions	O
,	O
possibly	O
relying	O
on	O
any	O
of	O
Session	B-Application
Initiation	I-Application
Protocol	I-Application
,	O
Extensible	B-Protocol
Messaging	I-Protocol
and	I-Protocol
Presence	I-Protocol
Protocol	I-Protocol
(	O
XMPP	B-Protocol
)	O
,	O
Message	B-Application
Queuing	I-Application
Telemetry	I-Application
Transport	I-Application
,	O
Matrix	B-Protocol
,	O
or	O
another	O
protocol	O
.	O
</s>
<s>
requires	O
implementations	O
to	O
provide	O
PCMA/PCMU	O
(	O
)	O
,	O
Telephone	O
Event	O
as	O
DTMF	O
(	O
)	O
,	O
and	O
Opus	B-Algorithm
(	O
)	O
audio	B-Algorithm
codecs	I-Algorithm
as	O
minimum	O
capabilities	O
.	O
</s>
<s>
The	O
PeerConnection	O
,	O
data	O
channel	O
and	O
media	O
capture	O
browser	B-Application
APIs	B-Application
are	O
detailed	O
in	O
the	O
W3C	O
specification	O
.	O
</s>
<s>
W3C	O
is	O
developing	O
ORTC	O
(	O
Object	B-Protocol
Real-Time	I-Protocol
Communications	I-Protocol
)	O
for	O
WebRTC	B-Protocol
.	O
</s>
<s>
WebRTC	B-Protocol
allows	O
browsers	B-Application
to	O
stream	O
files	O
directly	O
to	O
one	O
another	O
,	O
reducing	O
or	O
entirely	O
removing	O
the	O
need	O
for	O
server-side	O
file	O
hosting	O
.	O
</s>
<s>
WebTorrent	B-Protocol
uses	O
a	O
WebRTC	B-Protocol
transport	O
to	O
enable	O
peer-to-peer	O
file	O
sharing	O
using	O
the	O
BitTorrent	B-Protocol
protocol	I-Protocol
in	O
the	O
browser	B-Application
.	O
</s>
<s>
Some	O
file-sharing	O
websites	O
use	O
it	O
to	O
allow	O
users	O
to	O
send	O
files	O
directly	O
to	O
one	O
another	O
in	O
their	O
browsers	B-Application
,	O
although	O
this	O
requires	O
the	O
uploader	O
to	O
keep	O
the	O
tab	O
open	O
until	O
the	O
file	O
has	O
been	O
downloaded	O
.	O
</s>
<s>
A	O
few	O
CDNs	B-Operating_System
,	O
such	O
as	O
the	O
Microsoft-owned	O
Peer5	O
,	O
use	O
the	O
client	O
's	O
bandwidth	O
to	O
upload	O
media	O
to	O
other	O
connected	O
peers	O
,	O
enabling	O
each	O
peer	O
to	O
act	O
as	O
an	O
edge	O
server	O
.	O
</s>
<s>
Although	O
initially	O
developed	O
for	O
web	B-Application
browsers	I-Application
,	O
WebRTC	B-Protocol
has	O
applications	O
for	O
non-browser	O
devices	O
,	O
including	O
mobile	O
platforms	O
and	O
IoT	B-Operating_System
devices	I-Operating_System
.	O
</s>
<s>
Examples	O
include	O
browser-based	O
VoIP	B-Application
telephony	I-Application
,	O
also	O
called	O
cloud	O
phones	O
or	O
web	B-Application
phones	I-Application
,	O
which	O
allow	O
calls	O
to	O
be	O
made	O
and	O
received	O
from	O
within	O
a	O
web	B-Application
browser	I-Application
,	O
replacing	O
the	O
requirement	O
to	O
download	O
and	O
install	O
a	O
softphone	O
.	O
</s>
<s>
WebRTC	B-Protocol
is	O
supported	O
by	O
the	O
following	O
browsers	B-Application
(	O
incomplete	O
list	O
;	O
oldest	O
supported	O
version	O
specified	O
)	O
:	O
</s>
<s>
GStreamer	B-Language
directly	O
provides	O
a	O
free	O
WebRTC	B-Protocol
implementation	O
.	O
</s>
<s>
WebRTC	B-Protocol
establishes	O
a	O
standard	O
set	O
of	O
codecs	B-General_Concept
which	O
all	O
compliant	O
browsers	B-Application
are	O
required	O
to	O
implement	O
.	O
</s>
<s>
Some	O
browsers	B-Application
may	O
also	O
support	O
other	O
codecs	B-General_Concept
.	O
</s>
<s>
In	O
January	O
2017	O
,	O
TorrentFreak	O
reported	O
a	O
serious	O
security	B-Application
flaw	O
in	O
browsers	B-Application
supporting	O
WebRTC	B-Protocol
,	O
that	O
compromised	O
the	O
security	B-Application
of	O
VPN	B-Application
tunnels	O
by	O
exposing	O
a	O
user	O
's	O
true	O
IP	B-Protocol
address	I-Protocol
.	O
</s>
<s>
The	O
IP	B-Protocol
address	I-Protocol
read	O
requests	O
are	O
not	O
visible	O
in	O
the	O
browser	B-Application
's	O
developer	O
console	O
,	O
and	O
they	O
are	O
not	O
blocked	O
by	O
most	O
ad	O
blocking	O
,	O
privacy	O
and	O
security	B-Application
add-ons	O
,	O
enabling	O
online	O
tracking	O
despite	O
precautions	O
.	O
</s>
<s>
It	O
has	O
been	O
reported	O
that	O
the	O
cause	O
of	O
the	O
address	O
leak	O
is	O
not	O
a	O
bug	O
that	O
can	O
be	O
patched	O
,	O
but	O
is	O
foundational	O
to	O
the	O
way	O
WebRTC	B-Protocol
operates	O
;	O
however	O
,	O
there	O
are	O
several	O
solutions	O
to	O
mitigate	O
the	O
problem	O
.	O
</s>
<s>
WebRTC	B-Protocol
leakage	O
can	O
be	O
tested	O
for	O
,	O
and	O
solutions	O
are	O
offered	O
for	O
most	O
browsers	B-Application
.	O
</s>
<s>
WebRTC	B-Protocol
can	O
be	O
disabled	O
,	O
if	O
not	O
required	O
,	O
in	O
most	O
browsers	B-Application
.	O
</s>
<s>
The	O
uBlock	B-Protocol
Origin	I-Protocol
add-on	O
can	O
fix	O
this	O
problem	O
(	O
as	O
some	O
browsers	B-Application
now	O
fix	O
this	O
problem	O
by	O
themselves	O
,	O
from	O
uBlock	B-Protocol
Origin	I-Protocol
v1.38	O
onwards	O
this	O
option	O
has	O
been	O
disabled	O
on	O
these	O
browsers	B-Application
)	O
.	O
</s>
