<s>
The	O
Simple	B-Protocol
Gateway	I-Protocol
Control	I-Protocol
Protocol	I-Protocol
(	O
SGCP	B-Protocol
)	O
is	O
a	O
communications	O
protocol	O
used	O
within	O
a	O
voice	B-Application
over	I-Application
Internet	I-Application
Protocol	I-Application
(	O
VoIP	B-Application
)	O
system	O
.	O
</s>
<s>
It	O
has	O
been	O
superseded	O
by	O
the	O
Media	B-Protocol
Gateway	I-Protocol
Control	I-Protocol
Protocol	I-Protocol
(	O
MGCP	O
)	O
,	O
another	O
implementation	O
of	O
the	O
media	B-Protocol
gateway	I-Protocol
control	I-Protocol
protocol	I-Protocol
architecture	O
.	O
</s>
<s>
The	O
Simple	B-Protocol
Gateway	I-Protocol
Control	I-Protocol
Protocol	I-Protocol
was	O
published	O
in	O
several	O
Internet	O
Engineering	O
Task	O
Force	O
(	O
IETF	O
)	O
draft	O
versions	O
between	O
May	O
and	O
July	O
1998	O
by	O
Mauricio	O
Arango	O
and	O
Christian	O
Huitema	O
,	O
at	O
Telcordia	O
Technologies	O
(	O
formerly	O
Bellcore	O
)	O
.	O
</s>
<s>
The	O
protocol	O
architecture	O
decomposes	O
a	O
telecommunications	O
gateway	O
located	O
at	O
the	O
boundary	O
between	O
the	O
public	O
switched	O
telephone	O
network	O
and	O
an	O
Internet	B-Protocol
Protocol	I-Protocol
(	O
IP	O
)	O
network	O
,	O
such	O
as	O
the	O
Internet	O
,	O
into	O
a	O
media	O
gateway	O
controller	O
(	O
MGC	O
)	O
on	O
the	O
IP	O
network	O
,	O
providing	O
call	O
and	O
device	O
control	O
,	O
and	O
multiple	O
media	O
gateways	O
(	O
MGs	O
)	O
that	O
handle	O
the	O
actual	O
media	O
conversion	O
to	O
the	O
analog	O
or	O
digital	O
circuits	O
of	O
the	O
PSTN	O
,	O
or	O
simply	O
connect	O
residential	O
telephones	O
.	O
</s>
<s>
Communication	O
between	O
multiple	O
media	O
gateway	O
controllers	O
is	O
handled	O
by	O
other	O
protocols	O
,	O
such	O
as	O
the	O
Session	B-Application
Initiation	I-Application
Protocol	I-Application
(	O
SIP	O
)	O
.	O
</s>
<s>
Shortly	O
after	O
its	O
publication	O
,	O
SGCP	B-Protocol
was	O
merged	O
with	O
the	O
Internet	B-Protocol
Protocol	I-Protocol
Device	I-Protocol
Control	I-Protocol
(	O
IPDC	O
)	O
proposal	O
sponsored	O
by	O
Level3	O
Communications	O
in	O
the	O
Fall	O
of	O
1998	O
.	O
</s>
<s>
This	O
led	O
to	O
the	O
definition	O
of	O
the	O
Media	B-Protocol
Gateway	I-Protocol
Control	I-Protocol
Protocol	I-Protocol
,	O
jointly	O
submitted	O
to	O
the	O
IETF	O
by	O
the	O
authors	O
of	O
SGCP	B-Protocol
and	O
IPDC	O
in	O
October	O
1998	O
.	O
</s>
