<s>
Discovery	B-Protocol
and	I-Protocol
Launch	I-Protocol
(	O
DIAL	O
)	O
is	O
a	O
protocol	O
co-developed	O
by	O
Netflix	O
and	O
YouTube	B-General_Concept
with	O
help	O
from	O
Sony	O
and	O
Samsung	B-Application
.	O
</s>
<s>
It	O
is	O
a	O
mechanism	O
for	O
discovering	O
and	O
launching	O
applications	O
on	O
a	O
single	O
subnet	B-Protocol
,	O
typically	O
a	O
home	O
network	O
.	O
</s>
<s>
It	O
relies	O
on	O
Universal	B-Application
Plug	I-Application
and	I-Application
Play	I-Application
(	O
UPnP	B-Application
)	O
,	O
Simple	B-Protocol
Service	I-Protocol
Discovery	I-Protocol
Protocol	I-Protocol
(	O
SSDP	O
)	O
,	O
and	O
HTTP	B-Protocol
protocols	I-Protocol
.	O
</s>
<s>
The	O
protocol	O
works	O
without	O
requiring	O
a	O
pairing	B-Protocol
between	O
devices	O
.	O
</s>
<s>
It	O
was	O
formerly	O
used	O
by	O
the	O
Chromecast	B-Device
media	O
streaming	O
adapter	O
that	O
was	O
introduced	O
in	O
July	O
2013	O
by	O
Google	B-Application
.	I-Application
</s>
<s>
(	O
Chromecast	B-Device
now	O
uses	O
mDNS	B-Protocol
instead	O
of	O
DIAL	O
.	O
)	O
</s>
<s>
DIAL	O
enables	O
what	O
the	O
TV	O
industry	O
calls	O
second	O
screen	O
devices	O
,	O
such	O
as	O
tablet	B-Device
computers	I-Device
and	O
mobile	O
phones	O
to	O
send	O
content	O
to	O
first	O
screen	O
devices	O
,	O
such	O
as	O
televisions	O
,	O
Blu-ray	O
players	O
,	O
and	O
set-top	O
boxes	O
.	O
</s>
<s>
2nd	O
screen	O
:	O
a	O
smartphone	O
,	O
tablet	B-Device
,	O
or	O
similar	O
device	O
.	O
</s>
