<s>
Specification	B-Application
and	I-Application
Description	I-Application
Language	I-Application
(	O
SDL	O
)	O
is	O
a	O
specification	B-Application
language	I-Application
targeted	O
at	O
the	O
unambiguous	O
specification	O
and	O
description	O
of	O
the	O
behaviour	O
of	O
reactive	O
and	O
distributed	B-Architecture
systems	I-Architecture
.	O
</s>
<s>
The	O
Specification	B-Application
and	I-Application
Description	I-Application
Language	I-Application
provides	O
both	O
a	O
graphical	O
Graphic	O
Representation	O
(	O
SDL/GR	O
)	O
as	O
well	O
as	O
a	O
textual	O
Phrase	O
Representation	O
(	O
SDL/PR	O
)	O
,	O
which	O
are	O
both	O
equivalent	O
representations	O
of	O
the	O
same	O
underlying	O
semantics	O
.	O
</s>
<s>
A	O
system	O
is	O
specified	O
as	O
a	O
set	O
of	O
interconnected	O
abstract	O
machines	O
which	O
are	O
extensions	O
of	O
finite	B-Architecture
state	I-Architecture
machines	I-Architecture
(	O
FSM	O
)	O
.	O
</s>
<s>
The	O
language	O
is	O
formally	B-Algorithm
complete	I-Algorithm
,	O
</s>
<s>
The	O
Specification	B-Application
and	I-Application
Description	I-Application
Language	I-Application
covers	O
five	O
main	O
aspects	O
:	O
structure	O
,	O
communication	O
,	O
behavior	O
,	O
data	O
,	O
and	O
inheritance	O
.	O
</s>
<s>
This	O
version	O
is	O
accompanied	O
by	O
a	O
UML-Profile	O
:	O
ITU-T	O
Recommendation	O
Z.109	O
(	O
04/12	O
)	O
,	O
SDL-2010	O
combined	O
with	O
UML	B-Language
.	O
</s>
<s>
SDL-2010	O
also	O
introduced	O
the	O
support	O
of	O
C	O
data	O
types	O
as	O
initially	O
introduced	O
by	O
SDL-RT	B-Application
.	O
</s>
<s>
The	O
lowest	O
level	O
block	O
is	O
composed	O
of	O
one	O
process	O
or	O
several	O
processes	O
described	O
as	O
finite	B-Architecture
state	I-Architecture
machines	I-Architecture
.	O
</s>
<s>
Each	O
process	O
agent	O
is	O
a	O
state	B-Architecture
machine	I-Architecture
that	O
contributes	O
to	O
the	O
action	O
carried	O
out	O
by	O
the	O
system	O
.	O
</s>
<s>
When	O
the	O
state	B-Architecture
machine	I-Architecture
is	O
waiting	O
in	O
a	O
state	O
,	O
if	O
the	O
first	O
signal	O
in	O
the	O
input	O
port	O
is	O
enabled	O
for	O
that	O
state	O
it	O
starts	O
a	O
transition	O
leading	O
to	O
another	O
state	O
.	O
</s>
<s>
A	O
connection	O
request	O
message	O
conReq	O
is	O
sent	O
,	O
a	O
5	O
seconds	O
timer	O
conReqTimer	O
is	O
started	O
,	O
and	O
the	O
state	B-Architecture
machine	I-Architecture
goes	O
to	O
the	O
connecting	O
state	O
.	O
</s>
<s>
If	O
a	O
connection	O
confirmation	O
is	O
received	O
the	O
state	B-Architecture
machine	I-Architecture
goes	O
to	O
connected	O
state	O
.	O
</s>
<s>
SDL-RT	B-Application
is	O
based	O
on	O
the	O
ITU	O
Specification	B-Application
and	I-Application
Description	I-Application
Language	I-Application
replacing	O
the	O
data	O
language	O
with	O
C	O
.	O
Latest	O
version	O
of	O
SDL	O
standard	O
(	O
SDL'2010	O
)	O
now	O
includes	O
the	O
support	O
of	O
C	O
data	O
types	O
and	O
syntax	O
making	O
SDL-RT	B-Application
basic	O
principle	O
part	O
of	O
the	O
official	O
standard	O
.	O
</s>
<s>
TNSDL	B-Language
is	O
a	O
variant	O
developed	O
by	O
Nokia	O
for	O
their	O
internal	O
use	O
.	O
</s>
<s>
MSC	O
Message	B-Application
Sequence	I-Application
Chart	I-Application
.	O
</s>
<s>
ASN.1	B-Protocol
Abstract	B-Protocol
Syntax	I-Protocol
Notation	I-Protocol
One	I-Protocol
.	O
</s>
<s>
TTCN-3	B-Protocol
Testing	O
and	O
Test	O
Control	O
Notation	O
version	O
3	O
.	O
</s>
<s>
Unified	B-Language
Modeling	I-Language
Language	I-Language
A	O
generic	O
modeling	O
notation	O
.	O
</s>
