<s>
Iberpac	B-Protocol
(	O
or	O
Red	O
UNO	O
)	O
was	O
the	O
Spanish	O
packet	B-Protocol
switched	I-Protocol
X.25	B-Protocol
data	B-Architecture
network	I-Architecture
.	O
</s>
<s>
Iberpac	B-Protocol
lents	O
its	O
name	O
to	O
Iberpac	B-Protocol
Plus	O
and	O
Iberpac	B-Protocol
Básico	O
,	O
the	O
latest	O
X.25	B-Protocol
services	O
in	O
Spain	O
.	O
</s>
<s>
Iberpac	B-Protocol
evolved	O
from	O
the	O
Spanish	O
Red	O
Especial	O
de	O
Transmisión	O
de	O
Datos	O
(	O
RETD	O
)	O
,	O
the	O
world	O
's	O
first	O
public	O
data	B-Architecture
network	I-Architecture
.	O
</s>
<s>
Created	O
in	O
1971	O
,	O
RETD	O
was	O
based	O
on	O
general-purpose	O
Univac	B-Device
418	I-Device
III	O
computers	O
.	O
</s>
<s>
Some	O
of	O
the	O
design	O
principles	O
of	O
TESYS	O
nodes	O
were	O
advanced	O
for	O
their	O
time	O
(	O
multithreading	B-General_Concept
,	O
token	B-Protocol
passing	I-Protocol
protocols	O
)	O
.	O
</s>
<s>
In	O
contrast	O
,	O
the	O
large	O
user	O
base	O
with	O
terminals	O
based	O
on	O
legacy	O
RSAN	O
protocols	O
slowed	O
the	O
adoption	O
of	O
X.25	B-Protocol
,	O
TESYS	O
product	O
development	O
and	O
support	O
were	O
targeted	O
to	O
CTNE	O
only	O
(	O
thus	O
precluding	O
the	O
spread	O
of	O
TESYS	O
to	O
international	O
markets	O
)	O
and	O
data	O
lines	O
in	O
Spain	O
became	O
slow	O
for	O
their	O
time	O
(	O
only	O
2%	O
lines	O
above	O
1200	O
bit/s	O
in	O
Spain	O
in	O
1982	O
,	O
compare	O
89%	O
in	O
West	O
Germany	O
)	O
.	O
</s>
<s>
Renamed	O
as	O
IBERPAC	B-Protocol
,	O
the	O
network	O
evolved	O
to	O
X.25	B-Protocol
in	O
the	O
1980s	O
,	O
and	O
it	O
was	O
renamed	O
again	O
as	O
'	O
Red	O
UNO	O
 '	O
in	O
the	O
1990s	O
.	O
</s>
<s>
IBERPAC	B-Protocol
enabled	O
new	O
videotex	B-Operating_System
and	O
teletext	O
services	O
,	O
although	O
the	O
adoption	O
lagged	O
far	O
behind	O
the	O
popularity	O
of	O
similar	O
services	O
in	O
other	O
countries	O
,	O
such	O
as	O
the	O
French	O
Minitel	B-Application
.	O
</s>
<s>
Until	O
December	O
31	O
,	O
2015	O
,	O
Red	O
UNO	O
supported	O
two	O
legacy	O
X.25	B-Protocol
services	O
:	O
flat-rate	O
Iberpac	B-Protocol
Plus	O
and	O
pay-per-use	O
Iberpac	B-Protocol
Básico	O
.	O
</s>
<s>
Iberpac	B-Protocol
services	O
were	O
targeted	O
to	O
corporate	O
customers	O
with	O
specific	O
reliability	O
demands	O
.	O
</s>
