<s>
The	O
program	O
ttcp	B-Protocol
(	O
Test	O
TCP	B-Protocol
)	O
is	O
a	O
utility	O
for	O
measuring	O
network	O
throughput	O
,	O
popular	O
on	O
Unix	B-Application
systems	I-Application
.	O
</s>
<s>
It	O
measures	O
the	O
network	O
throughput	O
between	O
two	O
systems	O
using	O
the	O
TCP	B-Protocol
or	O
optionally	O
UDP	B-Protocol
protocols	I-Protocol
.	O
</s>
<s>
It	O
was	O
written	O
by	O
Mike	O
Muuss	O
and	O
Terry	O
Slattery	O
at	O
BRL	O
sometime	O
before	O
December	O
1984	O
,	O
to	O
compare	O
the	O
performance	O
of	O
TCP	B-Protocol
stacks	I-Protocol
by	O
the	O
Computer	B-Operating_System
Systems	I-Operating_System
Research	I-Operating_System
Group	I-Operating_System
(	O
CSRG	B-Operating_System
)	O
of	O
the	O
University	O
of	O
California	O
,	O
Berkeley	O
and	O
Bolt	O
,	O
Beranek	O
and	O
Newman	O
(	O
BBN	O
)	O
to	O
help	O
DARPA	O
decide	O
which	O
version	O
to	O
place	O
in	O
4.3BSD	B-Operating_System
.	O
</s>
<s>
Many	O
compatible	O
implementations	O
and	O
derivatives	O
exist	O
including	O
the	O
widely	O
used	O
Iperf	B-Language
.	O
</s>
<s>
Testing	O
can	O
be	O
done	O
from	O
any	O
platform	O
to	O
any	O
other	O
platform	O
,	O
for	O
example	O
from	O
a	O
Windows	B-Application
machine	O
to	O
a	O
Linux	B-Application
machine	O
,	O
as	O
long	O
as	O
they	O
both	O
have	O
a	O
ttcp	B-Protocol
application	O
installed	O
.	O
</s>
<s>
For	O
normal	O
use	O
,	O
ttcp	B-Protocol
is	O
installed	O
on	O
two	O
machines	O
–	O
one	O
will	O
be	O
the	O
sender	O
,	O
the	O
other	O
the	O
receiver	O
.	O
</s>
<s>
The	O
statistics	O
output	O
covers	O
TCP/UDP	O
payload	O
only	O
(	O
not	O
protocol	O
overhead	O
)	O
and	O
is	O
generally	O
displayed	O
by	O
default	O
in	O
KiB/s	O
(	O
kibiBytes	O
per	O
second	O
)	O
instead	O
of	O
kb/s	O
(	O
kilobits	O
per	O
second	O
)	O
,	O
but	O
it	O
can	O
be	O
configured	O
to	O
be	O
displayed	O
in	O
other	O
ways	O
on	O
some	O
implementations	O
.	O
</s>
<s>
Originally	O
designed	O
for	O
Unix	B-Application
systems	I-Application
,	O
ttcp	B-Protocol
has	O
since	O
been	O
ported	O
to	O
and	O
reimplemented	O
on	O
many	O
other	O
systems	O
such	O
as	O
Windows	B-Application
.	O
</s>
<s>
The	O
original	O
Unix	B-Application
implementation	O
developed	O
by	O
Mike	O
Muuss	O
and	O
Terry	O
Slattery	O
,	O
version	O
1.10	O
dated	O
1987-09-02	O
.	O
</s>
<s>
Provides	O
additional	O
information	O
related	O
to	O
the	O
data	O
transfer	O
such	O
as	O
user	O
,	O
system	O
,	O
and	O
wall-clock	O
time	O
,	O
transmitter	O
and	O
receiver	O
CPU	O
utilization	O
,	O
and	O
loss	O
percentage	O
(	O
for	O
UDP	B-Protocol
transfers	O
)	O
.	O
</s>
<s>
Developed	O
by	O
Microsoft	O
,	O
used	O
to	O
profile	O
and	O
measure	O
Windows	B-Application
networking	O
performance	O
.	O
</s>
<s>
Developed	O
by	O
Shihua	O
Xiao	O
at	O
Microsoft	O
,	O
used	O
to	O
profile	O
and	O
measure	O
Linux	B-Application
networking	O
performance	O
.	O
</s>
<s>
Provided	O
multiple	O
threading	O
to	O
exchange	O
data	O
in	O
test	O
,	O
and	O
potentially	O
can	O
interop	O
with	O
Windows	B-Application
version	O
of	O
ntttcp	O
.	O
</s>
<s>
Native	O
Windows	B-Application
version	O
developed	O
by	O
PCAUSA	O
.	O
</s>
<s>
Cisco	B-Protocol
IOS	I-Protocol
routers	O
include	O
ttcp	B-Protocol
as	O
a	O
hidden	O
command	O
that	O
can	O
be	O
set	O
up	O
as	O
either	O
the	O
sender	O
or	O
receiver	O
in	O
version	O
11.2	O
or	O
higher	O
and	O
feature	O
sets	O
IP	O
Plus	O
(	O
is	O
-	O
images	O
)	O
or	O
Service	O
Provider	O
(	O
p	O
-	O
images	O
)	O
.	O
</s>
<s>
Many	O
EnGenius	O
branded	O
wireless	O
access	O
points	O
include	O
an	O
Iperf-based	O
implementation	O
accessible	O
as	O
Speed	O
Test	O
under	O
Diagnostics	O
in	O
the	O
web	O
and	O
command	O
line	O
user	O
interfaces	O
.	O
</s>
