<s>
Open	B-General_Concept
Transport	I-General_Concept
Network	I-General_Concept
(	O
OTN	O
)	O
is	O
a	O
flexible	O
private	O
communication	O
network	O
based	O
on	O
fiber	B-Architecture
optic	I-Architecture
technology	I-Architecture
,	O
manufactured	O
by	O
OTN	O
Systems	O
.	O
</s>
<s>
The	O
system	O
is	O
a	O
mix	O
of	O
Transmission	O
and	O
Access	O
NE	O
,	O
communicating	O
over	O
an	O
optical	B-Architecture
fiber	I-Architecture
.	O
</s>
<s>
RS232	O
)	O
as	O
well	O
as	O
telephony	O
(	O
POTS/ISDN	O
)	O
,	O
audio	O
,	O
Ethernet	O
,	O
video	O
and	O
video-over-IP	B-Protocol
(	O
via	O
M-JPEG	B-Application
,	O
MPEG2/4	O
,	O
H.264	B-Application
or	O
DVB	B-Application
)	O
(	O
)	O
.	O
</s>
<s>
Open	B-General_Concept
Transport	I-General_Concept
Network	I-General_Concept
is	O
a	O
brand	O
name	O
and	O
not	O
to	O
be	O
mistaken	O
with	O
Optical	B-Protocol
Transport	I-Protocol
Network	I-Protocol
.	O
</s>
<s>
The	O
basic	O
building	O
block	O
of	O
OTN	O
is	O
called	O
a	O
node	B-Protocol
.	O
</s>
<s>
The	O
remaining	O
node	B-Protocol
space	O
can	O
be	O
configured	O
with	O
up	O
to	O
8	O
(	O
different	O
)	O
layer	O
1	O
interfaces	O
as	O
required	O
.	O
</s>
<s>
OTN	O
nodes	O
are	O
interconnected	O
using	O
pluggable	B-Device
optical	B-Architecture
fibers	I-Architecture
in	O
a	O
dual	O
counterrotating	O
ring	B-Architecture
topology	I-Architecture
.	O
</s>
<s>
The	O
primary	O
ring	O
consists	O
of	O
fibers	O
carrying	O
data	O
from	O
node	B-Protocol
to	O
node	B-Protocol
in	O
one	O
direction	O
,	O
the	O
secondary	O
ring	O
runs	O
parallel	O
with	O
the	O
primary	O
ring	O
but	O
carries	O
data	O
in	O
the	O
opposite	O
direction	O
.	O
</s>
<s>
This	O
hot	B-General_Concept
standby	I-General_Concept
topology	O
results	O
in	O
a	O
1	O
+	O
1	O
path	O
redundancy	O
.	O
</s>
<s>
The	O
switchover	B-General_Concept
mechanism	O
is	O
hardware	O
based	O
and	O
results	O
in	O
ultrafast	O
(	O
50ms	O
)	O
switchover	B-General_Concept
without	O
service	O
loss	O
.	O
</s>
<s>
Virtual	O
bidirectional	O
point-to-point	B-Architecture
or	O
point-to-multipoint	B-General_Concept
connections	O
(	O
services	O
)	O
between	O
identical	O
interfaces	O
in	O
different	O
nodes	O
are	O
programmed	O
via	O
a	O
configuration	O
software	O
called	O
OMS	O
(	O
OTN	O
management	O
system	O
)	O
.	O
</s>
<s>
This	O
concept	O
makes	O
the	O
Open	B-General_Concept
Transport	I-General_Concept
Network	I-General_Concept
the	O
de	O
facto	O
transmission	O
backbone	B-General_Concept
standard	O
for	O
industrial	O
high	O
reliability	O
communication	O
sites	O
that	O
require	O
errorfree	O
communication	O
for	O
a	O
large	O
spectrum	O
of	O
protocols	O
over	O
long	O
distances	O
like	O
pipelines	O
,	O
metros	O
,	O
rail	O
,	O
motorways	O
and	O
industrial	O
sites	O
.	O
</s>
<s>
The	O
optical	O
rings	O
transport	O
frames	O
with	O
a	O
bitrate	O
of	O
(	O
approximately	O
)	O
150	O
Mbit/s	O
(	O
STM-1/OC	O
-3	O
)	O
,	O
622	O
Mbit/s	O
(	O
STM-4/OC	O
-12	O
)	O
,	O
2.5	O
Gbit/s	O
(	O
STM-16/OC	O
-48	O
)	O
or	O
10Gbit/s	O
(	O
STM-64/OC	O
-192	O
)	O
.	O
</s>
<s>
This	O
bandwidth	O
allocation	O
is	O
transferred	O
to	O
the	O
non-volatile	B-General_Concept
memory	I-General_Concept
of	O
the	O
control	O
boards	O
of	O
the	O
nodes	O
.	O
</s>
