<s>
UDP-based	B-Language
Data	I-Language
Transfer	I-Language
Protocol	I-Language
(	O
UDT	O
)	O
,	O
is	O
a	O
high-performance	O
data	O
transfer	O
protocol	O
designed	O
for	O
transferring	O
large	O
volumetric	O
datasets	O
over	O
high-speed	O
wide	O
area	O
networks	O
.	O
</s>
<s>
Such	O
settings	O
are	O
typically	O
disadvantageous	O
for	O
the	O
more	O
common	O
TCP	B-Protocol
protocol	I-Protocol
.	O
</s>
<s>
For	O
example	O
,	O
the	O
protocol	O
now	O
supports	O
rendezvous	O
connection	O
setup	O
,	O
which	O
is	O
a	O
desirable	O
feature	O
for	O
traversing	O
NAT	O
firewalls	O
using	O
UDP	B-Protocol
.	O
</s>
<s>
UDT	O
has	O
an	O
open	O
source	O
implementation	O
which	O
can	O
be	O
found	O
on	O
SourceForge	B-Application
.	O
</s>
<s>
The	O
UDT	O
project	O
started	O
in	O
2001	O
,	O
when	O
inexpensive	O
optical	O
networks	O
became	O
popular	O
and	O
triggered	O
a	O
wider	O
awareness	O
of	O
TCP	B-Protocol
efficiency	O
problems	O
over	O
high-speed	O
wide	O
area	O
networks	O
.	O
</s>
<s>
SABUL	O
used	O
UDP	B-Protocol
for	O
data	O
transfer	O
and	O
a	O
separate	O
TCP	B-Protocol
connection	O
for	O
control	O
messages	O
.	O
</s>
<s>
UDT2	O
removed	O
the	O
TCP	B-Protocol
control	O
connection	O
in	O
SABUL	O
and	O
used	O
UDP	B-Protocol
for	O
both	O
data	O
and	O
control	O
information	O
.	O
</s>
<s>
UDT2	O
also	O
introduced	O
a	O
new	O
congestion	O
control	O
algorithm	O
that	O
allowed	O
the	O
protocol	O
to	O
run	O
"	O
fairly	O
and	O
friendly	O
"	O
with	O
concurrent	O
UDT	O
and	O
TCP	B-Protocol
flows	O
.	O
</s>
<s>
UDT4	O
allowed	O
multiple	O
UDT	O
connections	O
to	O
bind	O
to	O
the	O
same	O
UDP	B-Protocol
port	O
and	O
it	O
also	O
supported	O
rendezvous	O
connection	O
setup	O
for	O
easier	O
UDP	B-Protocol
hole	O
punching	O
.	O
</s>
<s>
UDT	O
is	O
built	O
on	O
top	O
of	O
User	B-Protocol
Datagram	I-Protocol
Protocol	I-Protocol
(	O
UDP	B-Protocol
)	O
,	O
adding	O
congestion	O
control	O
and	O
reliability	O
control	O
mechanisms	O
.	O
</s>
<s>
The	O
UDT	O
implementation	O
exposes	O
a	O
set	O
of	O
variables	O
related	O
to	O
congestion	O
control	O
in	O
a	O
C++	B-Language
class	O
and	O
allows	O
users	O
to	O
define	O
a	O
set	O
of	O
callback	O
functions	O
to	O
manipulate	O
these	O
variables	O
.	O
</s>
<s>
Most	O
TCP	B-Protocol
control	O
algorithms	O
can	O
be	O
implemented	O
using	O
this	O
feature	O
with	O
fewer	O
than	O
100	O
lines	O
of	O
code	O
.	O
</s>
<s>
UDT	O
is	O
widely	O
used	O
in	O
high-performance	B-Architecture
computing	I-Architecture
to	O
support	O
high-speed	O
data	O
transfer	O
over	O
optical	O
networks	O
.	O
</s>
<s>
For	O
example	O
,	O
GridFTP	B-Application
,	O
a	O
popular	O
data	O
transfer	O
tool	O
in	O
grid	O
computing	O
,	O
has	O
UDT	O
available	O
as	O
a	O
data	O
transfer	O
protocol	O
.	O
</s>
<s>
Because	O
UDT	O
is	O
purely	O
based	O
on	O
UDP	B-Protocol
,	O
it	O
has	O
also	O
been	O
used	O
in	O
many	O
situations	O
where	O
TCP	B-Protocol
is	O
at	O
a	O
disadvantage	O
to	O
UDP	B-Protocol
.	O
</s>
<s>
Its	O
development	O
,	O
however	O
,	O
creates	O
new	O
vulnerabilities	O
because	O
like	O
many	O
other	O
protocols	O
,	O
it	O
relies	O
solely	O
on	O
the	O
existing	O
security	O
mechanisms	O
for	O
current	O
protocols	O
such	O
as	O
the	O
Transmission	B-Protocol
Control	I-Protocol
Protocol	I-Protocol
(	O
TCP	B-Protocol
)	O
and	O
UDP	B-Protocol
.	O
</s>
<s>
Research	O
conducted	O
by	O
Dr.	O
Danilo	O
Valeros	O
Bernardo	O
of	O
the	O
University	O
of	O
Technology	O
Sydney	O
,	O
a	O
member	O
of	O
the	O
Australian	O
Technology	O
Network	O
focusing	O
on	O
practical	O
experiments	O
on	O
UDT	O
using	O
their	O
proposed	O
security	O
mechanisms	O
and	O
exploring	O
the	O
use	O
of	O
other	O
existing	O
security	O
mechanisms	O
used	O
on	O
TCP/UDP	O
for	O
UDT	O
,	O
gained	O
interesting	O
reviews	O
in	O
various	O
network	O
and	O
security	O
scientific	O
communities	O
.	O
</s>
<s>
UDT	O
project	O
has	O
been	O
a	O
base	O
for	O
SRT	B-Protocol
project	O
,	O
which	O
uses	O
the	O
transmission	O
reliability	O
for	O
live	O
video	O
streaming	O
over	O
public	O
internet	O
.	O
</s>
<s>
The	O
UDT	O
team	O
has	O
won	O
the	O
prestigious	O
Bandwidth	O
Challenge	O
three	O
times	O
during	O
the	O
annual	O
ACM/IEEE	O
Supercomputing	B-Architecture
Conference	O
,	O
the	O
world	O
's	O
premier	O
conference	O
for	O
high-performance	B-Architecture
computing	I-Architecture
,	O
networking	O
,	O
storage	O
,	O
and	O
analysis	O
.	O
</s>
