<s>
NetBIOS	B-Protocol
Frames	I-Protocol
(	O
NBF	O
)	O
is	O
a	O
non-routable	O
network	B-Application
-	I-Application
and	O
transport-level	O
data	O
protocol	O
most	O
commonly	O
used	O
as	O
one	O
of	O
the	O
layers	O
of	O
Microsoft	B-Application
Windows	I-Application
networking	O
in	O
the	O
1990s	O
.	O
</s>
<s>
NBF	O
or	O
NetBIOS	B-Protocol
over	O
IEEE	O
802.2	O
LLC	O
is	O
used	O
by	O
a	O
number	O
of	O
network	O
operating	O
systems	O
released	O
in	O
the	O
1990s	O
,	O
such	O
as	O
LAN	B-Algorithm
Manager	I-Algorithm
,	O
LAN	B-Operating_System
Server	I-Operating_System
,	O
Windows	O
for	O
Workgroups	O
,	O
Windows	B-Application
95	I-Application
and	O
Windows	B-Device
NT	I-Device
.	O
</s>
<s>
Other	O
protocols	O
,	O
such	O
as	O
NBT	O
(	O
NetBIOS	B-Protocol
over	O
TCP/IP	O
)	O
,	O
and	O
NBX	O
(	O
NetBIOS-over-IPX/SPX	O
)	O
also	O
implement	O
the	O
NetBIOS/NetBEUI	O
services	O
over	O
other	O
protocol	O
suites	O
.	O
</s>
<s>
The	O
NBF	O
protocol	O
is	O
broadly	O
,	O
but	O
incorrectly	O
,	O
referred	O
to	O
as	O
NetBEUI	B-Protocol
.	O
</s>
<s>
This	O
originates	O
from	O
the	O
confusion	O
with	O
NetBIOS	B-Protocol
Extended	I-Protocol
User	I-Protocol
Interface	I-Protocol
,	O
an	O
extension	O
to	O
the	O
NetBIOS	B-Protocol
API	B-Application
that	O
was	O
originally	O
developed	O
in	O
conjunction	O
with	O
the	O
NBF	O
protocol	O
;	O
both	O
the	O
protocol	O
and	O
the	O
NetBEUI	B-Protocol
emulator	B-Application
were	O
originally	O
developed	O
to	O
allow	O
NetBIOS	B-Protocol
programs	O
to	O
run	O
over	O
IBM	O
's	O
new	O
Token	B-Device
Ring	I-Device
network	I-Device
.	O
</s>
<s>
Microsoft	O
caused	O
this	O
confusion	O
by	O
labelling	O
its	O
NBF	O
protocol	O
implementation	O
NetBEUI	B-Protocol
.	O
</s>
<s>
NBF	O
is	O
a	O
protocol	O
and	O
the	O
original	O
NetBEUI	B-Protocol
was	O
a	O
NetBIOS	B-Protocol
application	B-Application
programming	I-Application
interface	I-Application
extension	O
.	O
</s>
<s>
NBF	O
protocol	O
uses	O
802.2	O
type	O
1	O
mode	O
to	O
provide	O
the	O
NetBIOS/NetBEUI	O
name	O
service	O
and	O
datagram	B-Protocol
service	I-Protocol
,	O
and	O
802.2	O
type	O
2	O
mode	O
to	O
provide	O
the	O
NetBIOS/NetBEUI	O
session	O
service	O
(	O
virtual	B-Protocol
circuit	I-Protocol
)	O
.	O
</s>
<s>
NBF	O
protocol	O
makes	O
wide	O
use	O
of	O
broadcast	B-Operating_System
messages	O
,	O
which	O
accounts	O
for	O
its	O
reputation	O
as	O
a	O
chatty	O
interface	O
.	O
</s>
<s>
While	O
the	O
protocol	O
consumes	O
few	O
network	O
resources	O
in	O
a	O
very	O
small	O
network	O
,	O
broadcasts	B-Operating_System
begin	O
to	O
adversely	O
impact	O
performance	O
and	O
speed	O
when	O
the	O
number	O
of	O
hosts	O
present	O
in	O
a	O
network	O
grows	O
.	O
</s>
<s>
Sytek	O
developed	O
NetBIOS	B-Protocol
for	O
IBM	O
for	O
the	O
PC-Network	B-General_Concept
program	O
and	O
was	O
used	O
by	O
Microsoft	O
for	O
MS-NET	O
in	O
1985	O
.	O
</s>
<s>
In	O
1987	O
,	O
Microsoft	O
and	O
Novell	O
utilized	O
it	O
for	O
their	O
network	O
operating	O
systems	O
LAN	B-Algorithm
Manager	I-Algorithm
and	O
NetWare	B-Operating_System
.	O
</s>
<s>
Because	O
NBF	O
protocol	O
is	O
unroutable	O
it	O
can	O
only	O
be	O
used	O
to	O
communicate	O
with	O
devices	O
in	O
the	O
same	O
broadcast	B-Architecture
domain	I-Architecture
,	O
but	O
being	O
bridgeable	O
it	O
can	O
also	O
be	O
used	O
to	O
communicate	O
with	O
network	O
segments	O
connected	O
to	O
each	O
other	O
via	O
bridges	B-Protocol
.	O
</s>
<s>
This	O
means	O
that	O
NBF	O
is	O
only	O
well-suited	O
for	O
small	O
to	O
medium-sized	O
networks	B-Architecture
,	O
where	O
it	O
has	O
such	O
an	O
advantage	O
over	O
TCP/IP	O
that	O
requires	O
little	O
configuration	O
.	O
</s>
<s>
The	O
NetBIOS/NetBEUI	O
services	O
must	O
be	O
implemented	O
atop	O
other	O
protocols	O
,	O
such	O
as	O
IPX	O
and	O
TCP/IP	O
(	O
see	O
above	O
)	O
in	O
order	O
to	O
be	O
of	O
use	O
in	O
an	O
internetwork	O
.	O
</s>
<s>
NetBIOS/NetBEUI	O
provides	O
three	O
distinct	O
services	O
:	O
</s>
<s>
In	O
order	O
to	O
start	O
sessions	O
or	O
distribute	O
datagrams	B-Protocol
,	O
an	O
application	O
must	O
register	O
its	O
NetBIOS/NetBEUI	O
name	O
using	O
the	O
name	O
service	O
.	O
</s>
<s>
To	O
do	O
so	O
,	O
an	O
"	O
Add	O
Name	O
Query	O
"	O
or	O
"	O
Add	O
Group	O
Name	O
Query	O
"	O
packet	O
is	O
broadcast	B-Operating_System
on	O
the	O
network	O
.	O
</s>
<s>
If	O
the	O
NetBIOS/NetBEUI	O
name	O
is	O
already	O
in	O
use	O
,	O
the	O
name	O
service	O
,	O
running	O
on	O
the	O
host	O
that	O
owns	O
the	O
name	O
,	O
broadcasts	B-Operating_System
a	O
"	O
Node	O
Conflict	O
"	O
message	O
on	O
the	O
network	O
.	O
</s>
<s>
In	O
addition	O
,	O
to	O
start	O
a	O
session	O
or	O
to	O
send	O
a	O
datagram	B-Protocol
to	O
a	O
particular	O
host	O
rather	O
than	O
to	O
broadcast	B-Operating_System
the	O
datagram	B-Protocol
,	O
NBF	O
protocol	O
has	O
to	O
determine	O
the	O
MAC	B-Protocol
address	O
of	O
the	O
host	O
with	O
a	O
given	O
NetBIOS/NetBEUI	O
name	O
;	O
this	O
is	O
done	O
by	O
sending	O
a	O
"	O
Name	O
Query	O
"	O
packet	O
,	O
the	O
response	O
to	O
which	O
will	O
have	O
the	O
MAC	B-Protocol
address	O
of	O
the	O
host	O
sending	O
the	O
response	O
,	O
i.e.	O
</s>
<s>
Datagram	B-Protocol
mode	O
is	O
"	O
connectionless	B-Protocol
"	O
.	O
</s>
<s>
A	O
datagram	B-Protocol
is	O
sent	O
with	O
a	O
"	O
Datagram	B-Protocol
"	O
packet	O
if	O
it	O
is	O
being	O
sent	O
to	O
a	O
particular	O
NetBIOS/NetBEUI	O
name	O
,	O
or	O
a	O
"	O
Datagram	B-Protocol
Broadcast	B-Operating_System
"	O
packet	O
if	O
it	O
is	O
being	O
sent	O
to	O
all	O
NetBIOS/NetBEUI	O
names	O
on	O
the	O
network	O
.	O
</s>
<s>
Because	O
NetBIOS/NetBEUI	O
allows	O
packets	O
to	O
be	O
sent	O
that	O
are	O
larger	O
than	O
the	O
largest	O
packet	O
that	O
could	O
be	O
transmitted	O
on	O
a	O
particular	O
MAC	B-Protocol
layer	I-Protocol
,	O
a	O
NetBIOS/NetBEUI	O
packet	O
might	O
have	O
to	O
be	O
transmitted	O
as	O
a	O
sequence	O
of	O
"	O
Data	O
First	O
Middle	O
"	O
packets	O
and	O
a	O
"	O
Data	O
Only	O
Last	O
"	O
packet	O
;	O
packets	O
that	O
do	O
not	O
need	O
to	O
be	O
segmented	O
in	O
that	O
fashion	O
will	O
be	O
sent	O
as	O
a	O
single	O
"	O
Data	O
Only	O
Last	O
"	O
packet	O
.	O
</s>
<s>
NBF	O
protocol	O
–	O
apart	O
from	O
DOS	O
,	O
OS/2	B-Application
and	O
Unix	O
implementations	O
–	O
was	O
officially	O
supported	O
by	O
Microsoft	O
on	O
almost	O
every	O
version	O
of	O
Windows	O
up	O
to	O
Windows	B-Application
2000	I-Application
,	O
but	O
its	O
use	O
has	O
decreased	O
quickly	O
since	O
the	O
development	O
of	O
NBT	O
.	O
</s>
<s>
Microsoft	O
officially	O
dropped	O
support	O
starting	O
with	O
Windows	B-Application
XP	I-Application
,	O
but	O
it	O
is	O
included	O
on	O
the	O
Windows	B-Application
XP	I-Application
CD-ROM	O
and	O
can	O
be	O
installed	O
manually	O
.	O
</s>
<s>
Windows	O
Vista	O
does	O
not	O
include	O
NetBEUI	B-Protocol
(	O
means	O
NBF	O
)	O
support	O
at	O
all	O
,	O
but	O
the	O
Windows	B-Application
XP	I-Application
NetBEUI	B-Protocol
support	O
drivers	O
can	O
be	O
used	O
.	O
</s>
