<s>
In	O
computer	B-Architecture
networking	I-Architecture
,	O
telecommunication	O
and	O
information	O
theory	O
,	O
broadcasting	B-Operating_System
is	O
a	O
method	O
of	O
transferring	O
a	O
message	O
to	O
all	O
recipients	O
simultaneously	O
.	O
</s>
<s>
Broadcasting	B-Operating_System
can	O
be	O
performed	O
as	O
a	O
high-level	O
operation	O
in	O
a	O
program	O
,	O
for	O
example	O
,	O
broadcasting	B-Operating_System
in	O
Message	B-Application
Passing	I-Application
Interface	I-Application
,	O
or	O
it	O
may	O
be	O
a	O
low-level	O
networking	O
operation	O
,	O
for	O
example	O
broadcasting	B-Operating_System
on	O
Ethernet	O
.	O
</s>
<s>
All-to-all	B-Operating_System
communication	I-Operating_System
is	O
a	O
computer	B-Architecture
communication	I-Architecture
method	O
in	O
which	O
each	O
sender	O
transmits	B-Architecture
messages	I-Architecture
to	O
all	O
receivers	O
within	O
a	O
group	O
.	O
</s>
<s>
In	O
networking	O
this	O
can	O
be	O
accomplished	O
using	O
broadcast	B-Operating_System
or	O
multicast	O
.	O
</s>
<s>
This	O
is	O
in	O
contrast	O
with	O
the	O
point-to-point	B-Architecture
method	O
in	O
which	O
each	O
sender	O
communicates	O
with	O
one	O
receiver	O
.	O
</s>
<s>
There	O
are	O
four	O
principal	O
addressing	O
methods	O
in	O
the	O
Internet	B-Protocol
Protocol	I-Protocol
:	O
</s>
<s>
In	O
computer	B-Architecture
networking	I-Architecture
,	O
broadcasting	B-Operating_System
refers	O
to	O
transmitting	O
a	O
packet	B-Protocol
that	O
will	O
be	O
received	O
by	O
every	O
device	O
on	O
the	O
network	O
.	O
</s>
<s>
In	O
practice	O
,	O
the	O
scope	O
of	O
the	O
broadcast	B-Operating_System
is	O
limited	O
to	O
a	O
broadcast	B-Architecture
domain	I-Architecture
.	O
</s>
<s>
Broadcasting	B-Operating_System
is	O
the	O
most	O
general	O
communication	O
method	O
and	O
is	O
also	O
the	O
most	O
intensive	O
,	O
in	O
the	O
sense	O
that	O
many	O
messages	O
may	O
be	O
required	O
and	O
many	O
network	O
devices	O
are	O
involved	O
.	O
</s>
<s>
This	O
is	O
in	O
contrast	O
to	O
unicast	B-Protocol
addressing	O
in	O
which	O
a	O
host	O
sends	O
datagrams	B-Protocol
to	O
another	O
single	O
host	O
,	O
identified	O
by	O
a	O
unique	O
address	O
.	O
</s>
<s>
Broadcasting	B-Operating_System
may	O
be	O
performed	O
as	O
all	O
scatter	O
in	O
which	O
each	O
sender	O
performs	O
its	O
own	O
scatter	O
in	O
which	O
the	O
messages	O
are	O
distinct	O
for	O
each	O
receiver	O
,	O
or	O
all	O
broadcast	B-Operating_System
in	O
which	O
they	O
are	O
the	O
same	O
.	O
</s>
<s>
The	O
MPI	B-Application
message	B-Architecture
passing	I-Architecture
method	O
which	O
is	O
the	O
de	O
facto	O
standard	O
on	O
large	O
computer	B-Architecture
clusters	I-Architecture
includes	O
the	O
MPI_Alltoall	O
method	O
.	O
</s>
<s>
Not	O
all	O
network	O
technologies	O
support	O
broadcast	B-Operating_System
addressing	O
;	O
for	O
example	O
,	O
neither	O
X.25	B-Protocol
nor	O
Frame	B-Protocol
Relay	I-Protocol
have	O
broadcast	B-Operating_System
capability	O
.	O
</s>
<s>
The	O
Internet	B-Protocol
Protocol	I-Protocol
Version	I-Protocol
4	I-Protocol
(	O
IPv4	B-Protocol
)	O
,	O
which	O
is	O
the	O
primary	O
networking	O
protocol	O
in	O
use	O
today	O
on	O
the	O
Internet	O
and	O
all	O
networks	O
connected	O
to	O
it	O
,	O
supports	O
broadcast	B-Operating_System
,	O
but	O
the	O
broadcast	B-Architecture
domain	I-Architecture
is	O
the	O
broadcasting	B-Operating_System
host	O
's	O
subnet	O
,	O
which	O
is	O
typically	O
small	O
;	O
there	O
is	O
no	O
way	O
to	O
do	O
an	O
Internet-wide	O
broadcast	B-Operating_System
.	O
</s>
<s>
Broadcasting	B-Operating_System
is	O
largely	O
confined	O
to	O
local	B-General_Concept
area	I-General_Concept
network	I-General_Concept
(	O
LAN	B-General_Concept
)	O
technologies	O
,	O
most	O
notably	O
Ethernet	O
and	O
Token	B-Device
Ring	I-Device
,	O
where	O
the	O
performance	O
impact	O
of	O
broadcasting	B-Operating_System
is	O
not	O
as	O
large	O
as	O
it	O
would	O
be	O
in	O
a	O
wide	O
area	O
network	O
.	O
</s>
<s>
The	O
successor	O
to	O
IPv4	B-Protocol
,	O
IPv6	B-Protocol
does	O
not	O
implement	O
the	O
broadcast	B-Operating_System
method	O
,	O
so	O
as	O
to	O
prevent	O
disturbing	O
all	O
nodes	O
in	O
a	O
network	O
when	O
only	O
a	O
few	O
may	O
be	O
interested	O
in	O
a	O
particular	O
service	O
.	O
</s>
<s>
Instead	O
,	O
IPv6	B-Protocol
relies	O
on	O
multicast	O
addressing	O
-	O
a	O
conceptually	O
similar	O
one-to-many	O
routing	O
methodology	O
.	O
</s>
<s>
Both	O
Ethernet	O
and	O
IPv4	B-Protocol
use	O
an	O
all-ones	O
broadcast	B-Protocol
address	I-Protocol
to	O
indicate	O
a	O
broadcast	B-Operating_System
packet	I-Operating_System
.	O
</s>
<s>
Token	B-Device
Ring	I-Device
uses	O
a	O
special	O
value	O
in	O
the	O
IEEE	O
802.2	O
control	O
field	O
.	O
</s>
<s>
Broadcasting	B-Operating_System
may	O
be	O
abused	O
to	O
perform	O
a	O
type	O
of	O
DoS-attack	O
known	O
as	O
a	O
Smurf	O
attack	O
.	O
</s>
